I know it's possible, but how exactly I can do that? I am not able to find any specific tutorial. And will this protect me even if the website is not using HTTPS? Thanks regards!
There are different solutions for your question above.
First of all there are different VPN companies that offer VPN which routes the traffic through TOR thus airvpn and bestvpn.
Another solution can be that you are going to use whonix.
A less secure solution is that you connect first on your VPN for example openvpn and then you can use Tor Browser.
It should be very boring to explain here for example how whonix/openvpn/tor browser is working. I let you read and learn and find your best solution to your problem.