So the easiest way to level...

[Corkafish]

I'm in the same boat as you. I tried cooking first and was just overwhelmed by the amount of mats you need, so I switched to GSM, I'm up to lvl 10 but still feel lost lol

Up to 20 or so you can just fill out your crafting log and HQ the highest-level item that you can do reliably. Some guides recommend leveling up all professions to 15 before you focus on one, but I felt that only LTW (Waste Not), ALC (Tricks of the Trade), and CUL (Hasty Touch) were truly essential. These are abilities that you will use in every synthesis once you have access to them. GSM's Manipulation is also good but I've done fine without it.

After 20, tradecraft leves are the undisputed way to go.