Hi Larry and welcome aboard.
I don't feel competent to recommend a particular engine to you. But let's suppose you choose a 2 stroke, frame mount, chain drive type since that's what most newbies go with.
I bought two of them from thatsdax.com and I've been perfectly satisfied. There are other sponsors on the links to the left who have a good reputation around here. If you check out their websites you'll see photos of the engine kits and some basic info about them. They're not expensive. You could have one within a couple of weeks.
You don't need a lot of mechanical expertise to install them. If you can do an oil change or, say, change the brake pads on your car, then you're more than qualified. Though it's still a good idea to search these posts for hints. They can save you from making mistakes that could leave you high and dry while you wait for whichever part you need to replace.
So you ought to go for it. I don't think you'll be sorry. Very few people are.