A few random points:
1. Whatever it was that was causing you a problem, we could have probably told you how to fix it (and it wouldn't have cost you a penny) ;
2. It appears that, by 'fixing your problem', the computer technician has simply taken the easy way out and given you a clean installation of Windows (which means he's probably not much of an 'expert' anyway). ;
3. Free anti-virus programs are actually just part of full commercial security programs, so they're every bit as good as you'd get if you paid for the full product ;
4. What you don't get by going for a 'freebie' is a third-party firewall and anti-malware protection (which is different to anti-virus protection).
5. Most people don't bother with third-party firewalls, as they're happy to trust the one that's built into Windows. (You can include me in that group). However, if you want better '2- way' protection, the free firewall from Comodo is every bit as good as anything that you can pay for:
https://personalfirewall.comodo.com/
6. You can get excellent anti-malware protection for free by downloading and installing the free version of Malwarebytes Anti-Malware:
https://www.malwarebytes.org/antimalware/
(NB: When installing it, take care to deselect the pre-ticked option to take a free trial of the Premium version).
However you need to note that the free version is only 'run on demand' (rather than 'run in the background'). You need to remember to run a scan with it every so often; I suggest once per fortnight (or immediately if you suspect that you've got malware on your computer).
7. Any site that offers free streaming of professional football will be operating illegally. (Indeed, you're breaking the law by using such a site). So you shouldn't be too surprised if you get more than you bargained for when you access those sites!
8. If your computer is now, as you say, 'empty', what you'll need to install will depend upon your needs. I'd suggest a decent office suite, such as OpenOffice:
https://www.openoffice.org/
together with a good media player, such as either VLC
http://www.videolan.org/vlc/download-windows.en_GB.html
or GOM
https://www.gomlab.com/
together with an image viewer/editor, such as Irfanview
http://www.irfanview.com/
You might also like to consider one or more of the excellent freebies that Serif offer
http://www.freeserifsoftware.com/