I took a 15 mg adderall to make a long trip with no sleep one night. Friend gave it to me told me it would keep me awake. This is the only one I’ve ever taken and didn’t know it would come up on a screen. It has been 2 weeks since I took it. Will this show up on a hair test?

A hair test is meant to show consistent use over time. One time use, such as yours, would not show up in a hair test. I wouldn't lose any sleep over it.