Always start by red side on left side of the map. And on the right side of the map always start blue. You only start red on left if you're thinking about ganking bot lane.
Also you need to be looking at people's health bars and how far the lane is pushed in. Make sure you come from behind people for a gank. Also you want to be fighting monster in the fastest and least damaging ways possible which you can search up how to. Make sure you know what red and blue smite do and that you know that you can use them on enemy champions.
It depends of your champ actually. Some champ like shyvana or YI need to focus on farming early game. But if you play VI or Shaco, u have to gank very early.