They do need light to grow, yeah, but it doesn't need to be like some purple-hued grow lamp. Many (or most?) people just use regular white light bulbs — I think a pair of $10 flood bulbs should do the trick. If you're less concerned with maximizing yield you don't need to go too far down the road of optimizing your lighting set up at all.

here's a thorough guide to good light bulb options for growing — the author/curator of that sub is an electrician who's done a lot of research and testing on plant lights and lighting setups, especially for bucket grows. It can be pretty dense and you don't need to read or understand most of it — the post I linked has a pretty succinct summary of different bulbs at the bottom

Edit: I should note that especially if you're growing in a bucket, the light should be pretty much entirely sealed off from you