Another lefty here who plays right handed bass and guitar. I learned on family and friends instruments so I just learned playing right handed, no biggie. I'd try playing both ways in a shop if possible before you decide which to buy. (Even flipping a right handed bass over to left handed to get an idea of the feel, natural inclination) I'd also suggest renting first, or rent to own if you can find a place doing that. Or if you want to buy, $200-300 can buy a fine instrument.
Other notes: Neck length won't really matter to a beginner or make it easier to learn, I think. I wouldn't recommend starting on acoustic before going electric if it's electric bass you are interested in. Start playing on the instrument you want to play.
Other notes: Neck length won't really matter to a beginner or make it easier to learn, I think. I wouldn't recommend starting on acoustic before going electric if it's electric bass you are interested in. Start playing on the instrument you want to play.