What should i buy with 1k fg for my acc ? im currently lvl 17 and have no pokemon stronger than 900cp
you're also welcome to offer me here what u think is best for me atm

buy a level job levels are the most important in the game atm

Depends on what you want from the game.
If you want to collect em all, get some rare hunts.
If you want to fight gyms, level up.
If you want to hunt perfects, farm farm farm.