Re: first build!
Welcome Philly- Looks like it'll be a really nice build.
I see you have the sprocket mounted with the offset "dish" facing outward- This may or may not be the best allignment- you can probably even get a good idea even without the chain on first by just visually scoping it out from behind - maybe a straightedge yardstick would help- you want the wheel sprock on the same line with the motor sprock-
there is generally more frame clearance for the chain when the sprocket dish is turned the other way than how you have it now- but there really is no 'correct" way- it is whichever way it best lines up. Some of us don't use the chain tgensioner- that depends a lot on the individual set-up otherwise