Welcome!
First off, I highly recommend citistrip. Spray it on and let it soak for 10 minutes, then use a piece of brass or metal with a slight edge and scrape whatever has lifted off the stock. Luckily CVA used spray on finishes, so this should lift up easily.
Any trim like butt plates, triggers guards, leave them in place while sanding. To many guns have been ruined by folks refinishing stocks and leaving these parts off them. Leave them in place and after the stock is finished, you can then reblue or brown the trim.
Once you remove the stock finish, its pretty simple from there. I just recommend that you start with something like 100 grit until it looks smooth then start using 150 grit and finer. I use as fine as 2000 grit for a nice smooth finish.
Tung oil, tru oil, genuine oil. These are all easy to apply finishes that actually soak into the wood and bring the beauty out.
This isn't a refinish job. But it will show you how I keep the brass in place as i file an sand the stock. We want to see nice clean sharp edges, nothing rounded off and worst of all, we do not want to see brass sticking up past the wood. Keeping these places clean just adds to much to the overall look of the rifle.
https://www.frontiermuzzleloading.com/t10471-traditions-st-louis-hawken-build
This was my last gun build before neck surgery and she was a beauty. 2000 grit sand job and then 6 coats of birchwood casey genuine oil.