I don't know about the wheels.

To get started, I recommend a helmet and some comfortable wicking clothes, a water bottle and the tools and knowledge to change a flat tire. Always carry ID and a cell phone in case of emergency. Make sure the brakes work.

Then get on the bike and go for a few short rides.

The rest will follow, based on how you feel. If the saddle is not comfortable, if something starts to hurt (shoulders, knees, hands, whatever) then you can look into a fitting and/or finding a better saddle. You'll also get a sense of possible problems with the bike, e.g., if it doesn't shift smoothly, it needs a tune up.

Have fun!!