Couple of suggestions
Work slowly and you will find you need to stop. Just relax. You really won't make any mistakes. Well.... you will make a few mistakes. I strongly urge that you NEVER point out your mistakes and just get with it and most likely your "mistakes' will never be noticed by other people looking at your finished work!
I made plenty, but no one has noticed them. I am making another kit, Southern Mountain Rifle, and will do better! So will you!
Be careful taking the stock out of the box. It is very light weight. Don't ding it when handling.
Find Jim Kibler's youtube videos. He goes into detail. Part 1, Part 2, etc
Lock. I got a mainspring vise. Remove the mainspring and disassemble the lock. I used Jax. He sells it. Go slow with a small paintbrush. Light coats. Use same thing on your barrel. NOTE Install the sights BEFORE browning the barrel. Your dovetails may get slightly filled in and make it hard to install the sights later!
I got Maple stock. Not what to use with cherry. Jim will probably tell you. If nervous about stain, sand the barrel groove and try different stains. The barrel will cover that part.
Wet the stock with a rag. Let it dry and sand with 150 grit to get rid of whiskers. Do it twice. Test fit the barrel. put it in the channel, not yet for the wires. tighten the tang screw. Check the fit of the tang. If you are a real stickler, put a light coat of Prussian Blue (Amazon) on the metal. It will show any high spots. Get a good, small, sharp chisel. Or just don't worry about it.
The brass parts will have minor casting. Get a fine draw smooth file for the casting lines. Not a very big deal anyhow. You also can use the same "Smooth File" (Amazon) along the barrel and smooth out machine flaws.
A few minor tweaks. You will need to insert wires to hold barrel, trigger guard, thimbles- critical! Before driving in wires, smooth the driven in point so no sharp edges. Standardize and work on one side of the stock. I come in from the left. I also got a 1/16th drill bit, and drill about 1/4 inch from the right. The wire coming in can catch a splinter on the far side and pull a splinter. If you drill first, you should be ok.
My ramrod would not fit through the thimble or stock guard. I chucked mine in a drill and spun it with 80 grit until it fit. Then sand with 150 and then 220. Sliding the rod back and forth while sanding longitudinally.
Personally, I used "Wipe-on Poly" Home Depot for final stock. two coats rubbing with 0000 steel wool. Or 220 grit. If using SW, wipe down before adding coats of Poly or whatever you are final coat.
There is a longer screw to hold the lock to the side plate. The longer screw goes in the rearmost place.
The above will bond you and finish the rifle. BUT, it is pretty much finished as you get it. Several Friends just stain the stock, assemble it and go shooting!
Caveat: My advice is worth what you have paid <grin> I am a newbie in the above. Once you have finished your rifle and, therefore have lost your virginity, you can use what you have learned and help the next guy!
Good luck and good shooting! You have bought the best kit on the market.