+1 Good advice on going to a bike shop.
Your $1500 budget will put you in range of a wide variety of options, from high end “recreational” bikes to the first rungs of the hig-performance models. Plus they’ll be able to offer multiple sizes, so you’re more sure to be comfortable on the model you choose.
If you had a tighter budget, like $500, we’d definitely be happy to provide more used bike shopping tips, but with your budget; unless there’s a particular model or top-dollar feature that has your fancy; you’re far better served, as a “re-entry” rider, by starting with a bike from a shop.