Not sure exactly how to play 
Mostly his W.
It seems like you want to place it behind you enemy then all in, so if they run towards tower they are stuck in circle.
Is that about right?
Also if I'm getting ganked, I would throw it by my own tower, and run to it?
This is basically what you can do but there are a few more options. I try giving you some tips for combos, I have 200k on Ekko and i can say that my Ekko is pretty decent at this point.
the most important thing is to trade with wir E-Q combo, procc your passive and use the movement speed to run away or chase the enemy down even fruther. You can use your W in different ways, I'll show you some of my favourites. (W slows the enemies inside the circle, gives you a shield that scales with your AP and stuns EVERY enemy in the circle when you're standing in it too. Look out for a sweet 5man stun in teamfights) Always remember you can animation cancel your Q and W with your first E dash. In some situation this comes in very handy.
E-W-Q-E2 You use your E dash to Animation cancel the W, then throw out your Q to slow the enemy and prevent them from walking out of the circle. then you can use your 2nd E cast (the blink) to hop of the target and finish your combo, while they are getting stunned. This one is quite weird the first few times but if you get used to it its such a powerful combo since they dont see your W coming.
W-R when your being chased or ganked and your positive you can make a double kill you can place the w on your current sport, run away, wait for the enemies to walk into the circle and then ult right into it. Your ult teleports you into the W, stuns the enemies and deals A TON of dmg. Also most (especially low elp palyers like me lul) dont know how to deal with Ekkos chronobreak and wont see it coming. This takes a bit of timing and is risky but super fun and effective when used right.
(especially in teamfights) W-zhonyas-R Place your W in the middle of a teamfight, step in, Zhonyas. The enemies gonner hover around you waiting for you to kill you after your out of the stopwatch.They're gonna get stunned, you can ult to delete their healthbars. Super fun.
If you need any more help, feel free to ask. (Fuck now I'm in the mood to play some Ekko )
I hope I can help. Im an Ekko main with around 300k mastery points so I have a bit of knowledge on how he works. Prepare for an entire guide lmao.
First off runes, obviously Electrocute for primary, then its up to you what you have in the subclass. I have been experimenting with different ones, and both cheap shot and sudden impact work for him, especially if you can land your W for cheap shot, and sudden impact is just all around good. The next row is whatever you want, but I go eyeball collection because I dont find much use with Zombie ward and I always forget that I have ghost poro. Same thing with the final row, its whatever you deem good for you. I take ingenious hunter for the active item cooldown (Zhonyas and Protobelt), but ultimate hunter works well too. The other two are only if you particularly like healing or movement speed. For secondary tree, in this meta, Inspiration is the best. Take time warm tonic as the first one, and whatever you like best for the final. I determine it by the matchup, in a rough lane Id grab the stopwatch one or biscuit delivery, but in easy matchups Id get the boots. A good one regardless is Cosmic insight (CDR on Ekko is always good).
For items, I start Corrupting Potion for good sustain in lane and extra damage. Depending on the matchup you can either back and buy 2 dark seals or just go straight for protobelt (if u get 2 seals, sell one later for more gold. You buy the second one solely for the mana). Rush protobelt after the dark seals and then lich bane. It's situational after that. If you are fed, go for deathcap, if not, I love hourglass. Many people dont suggest taking it on Ekko but I always do. After protobelt, lich bane, deathcap/hourglass, its entirely up to you. Both void staff and morello are good. If they have a fed ap champ, then banshees veil is the way to go. Always get sorc boots, unless theyre all ad (tabi) or ap (merc treads).
On to gameplay. Basically, his early game sucks. You can't do much in most lanes, so just play safe and use your Q to farm from a distance. Always ping missing because most champs youre against will look to roam. When you hit level 3 you can look to trade, but you will use a ton of mana for your W, E, Q ideal trading combo in lane. Launch your W to where you think the enemy is GOING TO BE, not where he currently is. If you manage to get a stun off, by E'ing into the circle, finish your E animation onto the enemy and q right after it. Get the passive proc off and try to get electrocute off as well for extra damage, and then run out using your bonus MS. If you get fed, try to roam a lot. Ekko is 100% underrated and his damage output is off the charts when youre fed. The absolute best way to get good with your W is to just practice in game a ton. Try to predict where enemies will be and throw it there. It takes time, but the outplays are crazy if you master it.
During the mid game, it depends on how good you are doing. If you're behind, you will think you can still do damage, but you simply can't. At this point, go into a sidelane and afk farm until you have enough items. CS is crucial to Ekko. If you are fed or just not behind (so, even), then group with the team and try to set up fights with your W. A great initiation combo is setting up your W onto the enemy team (ideally the carry), and then pressed E, Flash, and Protobelt simultaneously and gap close like a mother fucker. Its hard to get used to, but when you do it surprises literally everyone on the map and can be the game winning play. If you fuck up in ANY situation, just R lmao.
Late game you are just beyond strong that you can duel really anyone. You completely decimate towers and youre wave clear is so efficient so you can splitpush really well if your team needs it. If you need to, sell your boots first for usually Spellbinder (to make up for the MS loss) and then sell protobelt if you need more damage. Get whatever you want in place of protobelt. If you dont sell items youll fall off in damage and you wont be as strong. After selling protobelt and boots, if you havent ended the game yet, then IDK what else you should sell. Ive never made it that far.
Combos: Land W stun, E, Q, skrt out with passive When youre running away from a squishy, try to put your ultimate ghost guy on them and R, then use E and Q and protobelt do try and kill them. Your 3rd passive hit on a champion with your Ult is some of the craziest damage in all of League. A really cheese combo I like is jumping into a group of people, pressing W ON YOURSELF and instantly pressing hourglass after it. Most people wont notice your ghost man hit the baseball thing and if anybody is near you when your W goes off, they will still be stunned even if you go golden. After that, it really is situational. Spamming R instantly is a good way to deter any CC coming your way and does good damage to the stunned enemies around you. Finish them off with E, protobelt, and Q. If you have spellbinder with a decent number of stacks, activate that also while ur in hourglass or after you press r for extra MS and damage.
There are more combos I can tell you about if you want them, but this was a lot to read so I hope you found this helpful and if you have any questions please feel free to ask. Ekko is a great champion and is a lot harder than everyone makes him out to be. A pretty high skill cap, crazy damage output, and great sustain in fights is everything youd want in an assassin/diver.
Enjoy, and good luck with your Ekko journey! :D
PS: You asked about when youre getting ganked where the W should be thrown. I put it on me when Im getting ganked because if they dive on me theyll likely get stunned and I can Auto+Q+Auto/run (letting return Q giving me speed boost) away and get that extra movement speed and avoid the gank.
