The most basic privacy is OS privacy and the best way to achieve OS pirvacy is to stop using windows.
If you want something easy to use just install Linux Mint
If you have to use windows you should use Windows AME which mitigates almost all of Windows telemetry. You can follow the instructions or get an ISO in their telegram group.
If AME is too extreme for your usecase, or reinstalling windows is too much trouble you can still reduce a lot of telemetry by running some of the scripts from privacy.sexy
antivirus is spyware. use this instead.