2) I was worried about findIng a job quickly.

2) I was worried about finding a job quickly. <-- this is correct and more natural

I was worred if ..... more common

Neither is correct. It should be "I was worried about whether or not I would find a job quickly"

2 is better. I come from America and we are tend to use the most concise ways of saying things. or... „I was worried if I could find a job quickly.“ #2 is still more natural Hope this helps, Kelli