Mute button is a wonderful ad beautiful feature in League of Legends. When you team up with a bunch of basement critters with zero manners and overall douches, you can trigger your anti toxicity shield, they can go AFK and die for what they worth.
Anyway, my overall suggestions for newer players are:
- Practice last hitting minions, since you only receive gold if you deal the last hit required to kill it. And also take your time to learn the effect of every item. In lower tiers, properly itemizing and steady gold income will have you a great advantage since most people in this level don't even bother with it and just copycat the item builds from their idol streamer.
- Pick simple champions at first. such as Garen/Trundle/Poppy/Pantheon/Kayle for warrior, soraka/Sona/Blitzcrank/Taric for support, Warwick or Nunu for jungle, Ashe/Sivir for marksman, Ryze/Annie/Fiddlesticks for mages. I would stay away from squishy assassins (Talon/Katarina/Fizz etc.) until you get better at avoiding skillshots.
- Always prioritize Objective taking rather than kills. Destroy a tower, keeps your minions wave doing a constant pressure in your line (by killing the enemy minion fast), kill dragon being jungle or with his help.
- Avoid dying to the enemy as much as possible. More deaths equals more money for them. More money for them better items they afford, and enemies with better items than you mean you can't duel them without help. Or even worse, you can't engage a teamfight for that.
- When you reach late game and the enemy team is stronger than your team. Is better to make diversion and have someone capable of doing split push. Split push is a maneuver to clear an entire line from enemy minion waves and towers. Tryndamere, Shyvana and Trundle are some that are good at it. The diversion is necessary to have enough time to perform splitpushing and avoid end up dying for a 5v1 enemy ambush.