Program = Bitcoin Core version v0.21.0
OS = Win 10
Sony VAIO

I constantly run the above. My question is no doubt a common one. If someone can point me to an existing topic that would be great. My newbie mistake was allowing a Pruned mode to run when I first installed a year ago. I had some bitcoins saved both at the wallet and in a back up on a USB. A few weeks ago I went to access my wallet and found I couldn't. I was given the "your are running a pruned node" advice. I was directed to rescan and found I couldn't do that due to pruned node. I'm currently waiting for the new software to catch up with all transactions.

I know that my wallet is stored as a .dat file. I now want to paste my saved wallet.dat file into the wallet folder and hopefully see my balance.

Is it just a matter of replacing my wallet.dat with the existing .dat file whilst the program is closed and then starting it up?
Is there a command I type to see the balance of my back up dat file?

If there is an existing thread on this basic topic somewhere please point me to it. Thank you in advance to anyone who can point me to some reading on commands generally and this topic in particular.