Hi there VazonJB.
just a couple of ideas (nothing big)
try reset smc/pmu and zap pram.
to do the first one, disconnect the power cable from the back of your iMac (shut the iMac down first), wait about 30 seconds. Hold down the power button on the back. After 30-- seconds. plug the power cable back in, wait another 30 seconds and press power button to start it up.
as it's starting up, do the second: Hold down Apple, Option, P and R keys together on the keyboard for 3 chimes (restarts). then let go of the keys and let iMac start up as usual.
I don't know exactly what model of Samsung external cd/dvd you have, but you might want to check samsung's website for any updates. You can find out what model of external cd you have by going to "About this Mac" then system report. It should be under Disc Burning.....or, you could look on the outer case of the external CD.
As for the scanner software, that's a snap. If you know the model number and the maker of your scanner, go to the maker's website and download the scanner software from there. Be advised though, you do have Catalina, which will not run 32 bit software of any kind. So you'd have to look for software that says in the description "works with/supports Catalina".
good luck to you
john b