You worry too much.
Have a competent AV, run CCleaner and Malwarebytes once in a while (I do on Sunday evening, have a decent backup. then get on with life.
Computers are designed to cope with millions of bytes, what may seem like too many to us are meat and drink to most PCs.
If you don't like the interface, there are folk out there trying to earn a living by helping you chose a suitable one. Make their day and employ them for an hour or so. Unless you get a cowboy, it'll be money well spent and life will be simpler thereafter.