How much motherboard and cpu do I need?

I always just drifted to Bestbuy when I needed pc parts. Its local and I can see what I am buying. I also always end up spending an arm and a legs for parts. Motherboards and cpus usually run up a $200-$300 bill. Now I need to build a pc and I can't afford that. So I went on Amazon and I see I can get a MB/CPU combo for about $100. Admittedly, many of them are 2, 3 or 4 years on the market. Some of them don't even require a fan. I thought all cpus needed a fan. Now I am wondering if I have been a fool to shop at Bestbuy for "new this year" parts. Apparently they only sell top of the line stuff. I didn't realize that I was paying for stuff that was way overkill for what I needed. At least thats what I came here to find out. So, for a desktop pc used for browsing, music, movies, etc (NO GAMING) what is actually needed? Are the MB/CPUs on this page adequate for my needs? https://www.amazon.com/s?k=cpu+mothe...f=sr_nr_p_36_3 What specs do I need to know about?