I wish to be the best support i can be but after last game i learned I'm not close to the level i thought i was. I'm not the best i can be and i really want to be better someone please help me. I play 
Sweet! I used to be a Nami main for about 2 years, and Sona was my go-to support for quite a while. I do have a little bit of experience with Morgana. I've been a support main ever since I started League (but i've been dabbling in midlane lately). I know all the nooks and crannies of being a good support. If you want to play with me, add me, but here are a few tips:
Find a support that fits you. You don't need to play one of these, but 
are probably the best supports right now. If you have the IP, buy one of them (I know you already have Nami). Some of these champs have a very high skillcap (Karma, Nautilus), but they are really worth it to learn. I was about to give up on the game until Karma came up on free week, I played her as support and fell in love. She is my main rn.
ALWAYS ALWAYS ALWAYS RUSH SIGHTSTONE/RUBY SIGHTSTONE. 
I cannot stress this enough. All lanes should be warding, but it is the support's job to ward objectives (dragon, baron, bushes, buffs, etc). Sightstone works on all supports, and should be used on all supports. Just work around your build and throw a sightstone in there in the first 10-20 minutes, or whenever you recall.
Play passively, unless you're a hyper-tank or engager, like or , you should not be a front-liner. Support's job during laning phase is to keep the adc alive and poke the enemies down, and then let the adc or jungle go in for the kill.
DO NOT TAKE CS OR FARM. It is painful how many supports I see farming all they want. The farm is for the AD Carry. There is one exception to this, and that is if the ADC is doing something else, like pushing or taking dragon, that you can clear a wave or two. Seriously, ADCs getting farm is crucial to the outcome of the game.
Don't be afraid to ask for ganks. Jungler should be ganking bot quite frequently, as bot is a difficult lane. Don't harass the jungler though! Let them farm or take dragon or gank another lane first, but make sure you at least get a little bit of help from them. (Mid can roam too, if they want)
Make sure your support has CC. CC is the one of the things that makes a support. If you do not have CC, you can not support. Along with this, I'd like to add that NOT ALL SUPPORTS NEED TO HAVE A HEAL OR SHIELD TO BE GOOD (although it is good to have). For example, Annie is a fantastic support who does not have any shields or heals. Remember, support's job is to lock down kills and support the team's objectives, like farming and dragon and baron and turrets. This leads me to my next point..
Don't play anything too off-meta just because it has a little bit of cc or it has a heal or shield. For example, LeBlanc support and Nidalee support do not work. It's painful how many of those I've seen. Don't even try it.
I know this is a given, but try not to steal kills. It is fine if you accidentally took 1 or 2 kills, or a teammate almost won a 1v1 but died and you're sure you can chase down the enemy, but once a support gets 4+ kills it's really pointless.
I hope this helps! If you need help with any supports, or have any more questions, just ask me.
Ok thank you for the tips it helps me a lot but i also need more training with the champs to understand them more like thresh his hook isnt instant he has a .25 to .5 sec delay so far thats what i notice about him I main morgana for a short time i stopped because i need to learn more of the support champs so now I'm main her again
Lol the tips the guy above gave you aren't very helpful to making you a better support. Those are just bronze support tips. Add me in game if you want real help. I'm a support main
