Welcome, welcome!! Hop on board and hang around, these ladies are amazing... and before long somebody else could say that about you :-)

Mainly get the bike that feels good **to you** - that's the one you'll get out and ride.

Bikes have gotten a LOT easier to ride since you were 16 :-) I recommend a bike shop as opposed to Wally World and what have you... you want to build a relationship with the bicycle and the activity, and a good bike shop will be able to guide you (and maybe give you the funny helmet cover they find in the back of the warehouse).