Welcome. Where are you located?
$1500 is a tight budget for a decent sib and an outboard, but it can be done. I would look at CL and FB marketplace for used tenders (dingys) as a package deal. I think you'll find a better deal if buying the boat and motor together.
If you want a smaller boat, any brand of small 10ft (3m) people use as dingys can be found. I'd get the newest boat you can, as the cheap PVC boats don't last more than maybe 10 years. Things start coming unglued. You can push these with approx an 8hp, and should plane with just you on board. 2 people prob won't plane.
If you want a little larger boat 12ft (3.5m ish) you should look for an older zodiac or avon in Hypalon, not PVC. These will be heavier duty, but will need more hp. At least 15hp. If I was getting a 12-13ft boat, I'd put a 20hp on it. A 14ft boat, I'd step up to 25hp.
You can't really go offshore with an electric trolling motor. You certainly can't plane. You should get an older 2 stroke motor- as opposed to a newer 4 stroke. Way more torque for the size and weight. It'll be louder and have some smoke but it is definitely the best choice for your budget.