First mistake is thinking you build an ARF. Some guy in China built it. You'll be assembling the modules.

I always use thinned epoxy (polyurethane wood finish will do) to fireproof the tank compartment. Not the whole inside - too much weight. I also epoxy strips of 2 oz fiberglass cloth inside the firewall down either side. Had the firewall pull off a G.P. Big Stik ARF (luckliy found before take-off) and have not trusted one since.

Lay out the hardware ahead of time. You don't want to use the wrong part, cut the longest rod if a shorter one is in the box, etc. I just assembled one that had extra wheel collars but was midding the landing gear bolts. Oops.

Do not cut the receiver antenna no matter how long it seems. It's a tuned wire and has to be that long.

Use 30 minute epoxy wherever epoxy is called for - just my preference.

Check the center of gravity twice and have someone else check it for you before you fly. There was just a post where a fellow got it wrong and augered in on his maiden and thought the supplier should send him a new plane. Nuh - uh.

The aileron goes up on the side you point it towards when you're standing behind the model. This is important. Right aileron = right aileron goes up.

Servo screws should be tight. But they're tiny and it doesn't take much strength. Don't ream the wood by over-tightening.

Ask lots of questions here if you get stuck. This is an astounding resource.

Have an experienced pilot do the trim (maiden) flight for you. They can be tricky. He/she will also do a good preflight and hopefully spot any glaring errors that would cost you the model in a crash.