There are certain apps you need.
There are malware protectors, system opitmisers, word processing programs, etc. Many of them charge real money.
Then there are free applications. Find them, use them, change them in case they start demanding money.
Don’t believe that only the expensive ones are valuable. Some free ones are better than the cash and carry.
One of the wisest moves you can make is downloading two different malware programs and running one then the other.
Those that can’t work in tandem, you can not use. Sometimes you have to download one program, run it, then delete it, and download another.
In this way, you don’t miss anything.
Those that don’t fight each other can sit together on your compute, but change them in tandem every month or so. First change this one, keeping that, next month change that one keeping this.
In this way you get the widest scope of protection.