I once used reducer to clean my bondo board and spreaders. it felt oily as I was mixing it after I did that so I paid close attention to how it feathered and it feathered like crap so I went back to bare metal.
One time I gargled my paint cup and forgot to re tighten the cap and the cap looked straight as if it was tightened and went to spray a little base out to clear the cap and it exploded out everywhere-lol
Twice in my life I have sprayed primer with no hardener. It was a pain to get off!!! Both times I was working overtime and was bound to leave right after it was primed. I guess I was in a hurry-lol
Don't be intimidated by a job. Be confident enough to remain calm and at your best but humble enough to know when to seek advice/help/ ideas. In other words, enjoy yourself and try your best.