Dont waste money on HF. Get one of the three - Lincoln, Miller, Hobart - or you will never learn to weld.
To take a class is the best way to start, before you buy anything. 110 box will weld everything on a motorcycle, the structural solution is as important as the weld quality.
My first project was Miging new exhaust for my jeep, but i am MSc in MechEng - I at least had the theorethical background, it was still very frustrating project using rented welder. You can borrow one for $50 bucks a day to give it a try.
Best project for beginner? Weld some angle iron frame, flat bars overlapping and such. The exhaust is thin walled, you will keep burning holes in it, dont ask me how I know:)