I've got to agree with bcr229.
Even though I think a BP isn't necessarily a 'bad' beginner snake for adults who know what they're doing (wouldn't really recommend them for teens or children unless a parent is doing most of the care) I think more temperate animals are better for beginners. As far as handling and bright display snakes go, garters are great. They're also one of the more active snakes, so you see your pet more often without having to dig them out of a hide.
Mainly, temperate animals are so much less complicated to keep than tropical/subtropical and are generally more forgiving if you don't get their temps exactly correct. Also I feel like BPs are often disappointing for people who expect to see their snake out and about.
That being said, if you have your heart set on a BP and know what you're doing, there's no reason you shouldn't get one