I main support and jungle, but I'm proficient in mid, and getting better with top and adc as well. I like to help people. When are you usually on? I might be able to help. Also I recommend picking up video capture software. You can watch your own games. That will help you far more than watching a streamer or pro. You can judge and learn from the exact situation you were in. You can calmly assess with all the time in the world what you did wrong or what you could've done better which isn't something you'll find watching someone else. Often times the the problem of people trying to get good watching streamers play is that the environment doesn't translate to low elo. What do I mean by that? They have teammates that rarely make the mistakes your teammates constantly make making things more difficult for you to deal with. On that note, you may not find a streamer at all who's often in the situations you're in. Another problem is that the decision making, tactics, and mistakes they do make are things you probably won't see at low elo so it doesn't even apply. That whole mindset is completely different. It still takes me a couple of games to switch gears when I join my plat friends coming from silver mentality. There's more confidence in game knowledge and lot of things that drive their decision-making you won't see. Watching streamers and pros play isn't an efficient way to learn. You might pick up a trick here or there, but why they do things is usually lost on most players.
You'll want tutorials specifically. Here is a series I recommend everyone watch.
https://www.youtube.com/watch?v=iko2tqmDpJQ&list=PL9RdXhXESRJzgY_SwHB8T-cZxXljWhQvz&index=1
Even then though, you have the section of "teamfighting" which is remarkably good and everyone should still watch it, but in gold and below it doesn't really apply because it assumes that your teammates have that same strategy and knowledge. You could stick to what the video says while all your teammates stupidly dive backline and you'll know it was dumb move, but if you back out thinking, "They fucked up" it could cost you the game. Inversely, ignoring the wise decision to back off and diving with them may net you a few kills or even victory because... well, low elo. The smarter engage and decision making doesn't always win. Sometimes diving a bad fight before your teammates get low on health works_really_ well in bronze and silver; less so in gold; rarely in plat unless you know what you're doing.
So then does nothing apply? Not necessarily. Having the game knowledge gives you a foundation to fall back on when you're struggling to get your bearings. If you have a foundation with anything, be it work, school, parenting, hobbies, games you'll be more effective because you won't lose your cool as easily because you don't know what to do. In the case of fast-paced decision-making activities like LoL you won't lose seconds trying to figure out what to do. The seconds you spend trying to think are all the time it takes to lose a teamfight. The problem with most players in bronze and silver is that their foundation gets them killed. They fall back on bad habits when the situation they like falls through and it get them killed. It all happens very quickly, but as as example, say you're bot with Ashe and Thresh. Thresh is used to landing his hooks. He's very good at it. You're on a winning streak with him. Say he misses when the enemy Alistar jumps on you. What now? He panics and burns all his cooldowns trying to get him off when all he had to do was flay the enemy Vayne away. Vayne gets a double kill. If he had flayed Vayne away you'd both be hurtin from Ali and Vayne poke, but that's your reward for getting caught in the first place. Nothing to sweat. Back off and play passive or b and come back. Turret isn't worth your life. If they kill you they'll probably get it too anyway.
It begins with building a foundation for yourself that is consistent. Your decision-making for any given game comes from your adaptability as a human being. Nothing else. Can you adapt? If I see the enemy team is picking up a lot of CC, I'm picking up Sej over my other junglers. Her passive gives her tenacity. If I find my teammates don't ward (which they rarely will cuz fuck all) I pick up tracker's knife. Tracker's knife has been my absolute must-have buy for all jungle games. I then pick up sweeping lens to deny vision. I take it rain or shine because I learned the value of vision. When the map is lit up like Madison Square Garden and theirs is a nocturne ult I find games tend to be extremely one-sided. Some people like chilling or challenging smite. Based on their playstyle, good for them. I value ward clearing more. It fits my playstyle to do it that way too. Based on how I play I have no need for them. Personal preference is a factor! Ignore anyone who says it isn't. If you cater your runes, masteries, and items to your playstyle you'll be more effective. Setting up stuff for a playstyle you don't practice is wasteful on every front. Now that doesn't mean don't buy sightstone as a support or something like that, but consider, spooky ghosts or extra item slot? 20% item cd might actually be useful too? Decisions. Aside from a few things every patch, (like Camille who's going to be the bane of all things if she's released in her current state) most things can be adapted to in this game.
That said, mistakes are still mistakes. If your playstyle is to play frontline Riven and you give her defensive runes and masteries things are not likely to work out well for you. You will often have to learn a new way to play. Every champion is different and although most can be played with basic foundational knowledge, there's a severe cap on what you can get out of them in terms of effectiveness if you're not using them correctly. I may have just confused you. :P
Just watch the tutorials. If you get recording software, post it online somewhere and link. I might be able to help.
and 
main i know a thing or two about decision making and mid game team fighting. I've taught 3 of my friends how to play this game (1 of which is better player than me now) and my best friend is one of the most aggressive support mains i've ever seen, he has a first blood ratio of freaking 52%. You can add me in game, i am on most of the time.
Good luck on the rift.