In addition to what all fellow members have written : buy a bikes that WORKS..rolls... shifts etc. AND can be PROVEN to do so.
ZERO repairs : Perfect wheels, No unique shifting, No..." jest neeeds a little adjusting"
NONE of it, exept for tires & a nicer saddle.......maybe, even that's a push.
Unless you're a mavin in bikes and/or have an extra hundred or so, buy functional.

You stated yourself "into shape" I don't read anything pertaining to learning mechanics.