What about left-handed playing?
If you’re left-handed, you can get a bass made especially for lefties. However, if you’ve never played bass or guitar before, I think you’re best off trying to play a normal right-handed instrument. They’re much easier to find and sometimes cheaper. Since you don’t have any starting knowledge, the experience of playing bass will be totally new whether you start left- or right-handed, so you might as well go right-handed.
Of course, there are famous left-handed bassists like Paul McCartney (the Beatles) and Jimmy Haslip (the Yellowjackets), and I’m not saying they were wrong to start leftie. I just want you to know that you don’t necessarily have to play left-handed just because you are generally left-hand dominant. I personally write and throw left-handed but play a normal right-handed bass.
If you’re left-handed, I think the best thing to do is go to the music store and try out both. See if one naturally feels easier than the other, and make your decision from there.