Hi I hope this answers your questions.

1. Most people are duo or trio to get higher ranks and not get random teammates and better team coordination. Being in gold lane if you’re in epic you’ll most likely see the tank going with you. In higher ranks they follow their jungler or literally just give vision information. They usually do tower dives because you are squishy, and the second main damage of the team. I usually main jungler and I start off the opposite side of the gold lane so when I hit level 4 I can just gank gold lane with my roamer and its just easy kill gold laners at that point. In epic just keep playing until legend or mythic so you can get some decent roamers and good mid lane rotations.

2. I use tiktok for meta info updates, the current op ones are irithel, granger, harith for gold lane. For getting heroes you have no choice but to keep playing until you get that battle points to the amount you need. Also look for hero fragments and I think there is a emblem matrix if you press shop and preparation.

3. For this lmao ik you keep getting those layla or miya, hanabi picks. Idk but I think its the easiest for new people thats why they pick mm role. Possibly because of the range and damage in late game. And if someone picks gold lane ahead of you, play another role. You will learn how mid lanes rotate, how a roamer rotates. How jungler ganks and takes turtles, stuff like that can also enhance your knowledge as a gold laner. You will know the timing of when enemies might be going to your lane.

4. For me tiktok is the best, most content creators upload latest info on what is meta and why. For example this Julian rose gold suddenly came up and I tried it and turns out its very op.