Guild Wars 2

Hi all, ive been playing engineer for a while and im still an overall noob to the game. My biggest problem is that i don’t know when to use which abilities. We have so many! when should i be using the flamethrower over my rifle? when should i be using tool kit or grenade kit over something else? Should i ever use gadgets? What skills are better than having a kit equipped? (how can one skill be better than 5?) these are a few of the questions i have about the class thanks for answering!

i tried this but im still getting the same problem op was having