Yes, I DID see where you said you read the manual. But all the necessary instructions are IN THE MANUAL.

I have assembled these ALPHA trainers for others, taking no more than 20 minutes to do so.

The bolt holes are on the lower bottom of the fuselage. You stick a bolt up through the bottom of the fuselage, through the top of the fuselage and into the stabilizer. You already should have bolted the fin to the stabilizer..

There's 2 bolts, and they're a little tricky to install, but it can be done. You may need a magnetic screwdriver to put them in place.

The "real" manual can be found online on the Horizon Hobby web site.

The prop nut is a HEX style, just as all Allen bolts are. What size is it? It's the size that fits the bolt. Experiment!

The one on the Evolution engine is metric, but I don't know what size it is.

If you plan to keep with this hobby, I'd suggest getting a set of both metric and standard Allen wrenches.

Maybe some other basic tools.

And keep looking for that hobby shop...