I would like to know what you recommend me to do. I am planning to install Photoshop CC but I do not know which version to get. I read that versions from 2020 have many issues and I understand people are returning to the 2019 version. Should I start with 2019 then, or, if I get the 2020 version will it include older versions for me to swap to if needed, or will I be stuck with a buggy 2020 version?
Your system specs are not stellar, but you should be able to run Photoshop CC reasonably comfortably.
The issues with the latest version V22.3.1 are centered around features that use the GPU and the Pen tool. If you are just going to be improving photographs that shouldn't be too much of a problem. However, if you do find 22.3.1 annoying to use, there's nothing stopping you from rolling back a few versions.
Open the Creative Cloud app, and click on the three dots to the right of Photoshop and chose Other Versions