Hi I am silver 5 and I am starting to main support which has led to me winning more games (not sure if a fluke or not). I already have Thresh Leona and Braum and I am working on my runes. I was wondering if any of you had some tips for a scrub like me.
For starters, I am not a high level player. I simply enjoy the game. but I do main support and I consider myself knowledgeable of the support role. I will address the game pattern itself for the role of support, and give some insight on some items which are valuable to support champs.
For a support champ a general rule is that you build a sight stone. Thats really the only general rule. You should never lock into any definite build path on a support champ. Your role in game is broken into 3 parts. part 1 is the laning phase, and your role is to disrupt the enemy adc from acquiring cs and to provide your adc with the means to win lane. This does not mean to give kills to your adc, there is a lot of misconception about that. Though generally its more beneficial for you to allow the adc to final shot enemy champs. Also during the first part, you should look to gank mid lane should the situation arise, because you're the team support, you're not the adc support. In situations where you might get a double in bot, and you have enough health you should travel up to mid to see if you can get a kill there as well. Although this isn't widely seen, a support gank gives a utility which many mid lane players aren't used to dealing with. That being said this takes practice and experience to know the appropriate time to attempt this gank.
The role you play in game post laning phase, or part 2 is that you're a second jungler. You're still not farming the jungle, but you're roaming and giving sight to the map. making sure lanes don't get pushed into you too much, and being available for battle. you should keep areas which are common battle grounds warded and sweep for enemy wards. This gives your team the ability to coordinate plans and communicate better. during this time in the game there typically arent any major team fights. but you should try to stay close to one of your allies given they may encounter an enemy or you do. In either case you have enough cc as a support to stall the fight long enough for your ally to kill them. Since you are limited to 3 wards and 1 pink you should opt to ward one jungle or the other just to provide the best possible vision. Hopefully your jungler wards the opposite jungle side, however many dont, its not your job to ward the entire map, remember that.
The third phase of the game is the end phase. This is typically when all out team fights will happen. In this current meta I believe the role of a support is to provide engages, and cc during team fights to keep your adc or carry in general alive long enough to kill the enemy team. I like items such as face of the mountain, iron locket, and randuins omen for the added shields and cc they provide in fights which are sometimes enough to keep your team alive in battle. Support items generally also double as tank items, and you can in the late game play the role as a utility tank quite well, dependent on your champion of choice.
There are sub divisions of support champs, tank supports, sustain supports, off meta supports, and "carry" supports. while the above "guide" is a basic how to play supports throughout the typical game each of these sub categories have their own unique roles.
I have provided examples of each sub category. Tank supports: Braum, Leona, Thresh, Taric Sustain supports: Nami, Bard, Janna, Sonna Off Meta (poke): Vel'Koz, Brand, Veigar, Anivia Carry supports: Annie
I didn't list every champion who plays support above, just a few to get the idea across.
If you are playing a support champion I highly suggest purchasing a support item, if nothing more then the gold income early game. If you are looking to build a support item to completion remember to build items that have good synergy with it. For example if you are playing Braum you might purchase face of the mountain, its active effect has good synergy with randuins omen over frozen heart, or for mmr it has better synergy with Locket over Banner of command. although each item has their place and unique situations when one is better than the other in game. again build for the game, do not build the same every game.
I wouldn't main support until gold 1 or 2. People at this elo are pretty bad tbh and you might be able to carry your lane, but that doesn't help if mid or top feeds.
Dont be afraid to die for your adc or your team
To be honest, the best way i can see what u need to work on is to play a few games with you. Other than that your just going to get the general info that you already know
Maining support myself, I can offer some fellow newbie advice.
Pick a lane bully that's not dependent on people following up on your initiates. I'd say of those three support champions you have, 
would probably be your best bet since he's able to harass the enemies enough to keep them on their toes AND his ice shield is a great way to keep your ADC safe from skillshots (and ults). 
is good for the whole run-away-because-I-exist factor, but he's so easily combated with smart positioning and you can't always depend on your ADC following up on a good hook.
also has some unique escape shenanigans (stacks-to-stun, decent move-speed, shield blocking ranged fire) to help you run off for a quick second to place down some much-needed wards.
One important thing I can say (from a support main) that hasn't been said already is knowing matchups.
Certain ADC's and Supports have such great synergy together, and can make things really easy in lane.
For example:
+ 
make a great team because of Leonas engage and CC. Plus Jinx has enough attack speed and bonus range to deal TONS of damage.
However,
+ don't make as good a combo because of Caitlyn's range and generally slower attack speed. Her all in capabilities are not as good as Jinx.
Then know your enemies and what supports work best against them.
Someone like 
is great against the hookers (at least at level 3+) like and 
because of Polymorph. Her disengage ability is outstanding. She can also greatly counter a 
engage.
That's some of the things I've noticed while playing.
