To switch to a road crank (the most common option is 50/34, other options are 48/32, 50/36, and more rarely 48/32 and 46/30) you'll need a road compatible flat bar front shifter and front derailleur in addition to the crankset. Don't worry about the BB--your bike uses a threaded BB shell and you can buy a BB to match whatever crank--it's a relatively minor cost in comparison to the crank itself and potentially the labor if you're paying for the work.

Also check out your shifter--is there a small switch on the underside? It may be a 3x compatible shifter as is, as they'll work with a double FD. If so you can get a 3x crank and derailleur.

I don't know what cadence you ride at and the speeds you need. If I were in Florida, I'd probably either keep the bike as is (as you can go faster than 25MPH if you can pedal 100RPM) or run it as a 1x with perhaps a slightly larger ring.