If you need a VPN, the best one I know of is proton. It isn't cheap, but as with most things you get what you pay for. They don't keep logs. If you connect via their Swiss sites you will also benefit from the very strong Swiss privacy laws. You can also access the Tor network from their portals, if you need to visit any .onion sites. A good VPN will prevent your ISP from seeing which sites you are visiting. However, it will not make any difference at all to what finishes up on your own computer, and ordinary browsing leaves behind a HUGE amount of information. You can't easily remove it. You need either technical knowledge or a good app. For securely erasing data from a PC that runs a Microsoft operating system, there are several apps available. The best one I know of is EastTec Eraser. Again, it isn't the cheapest product out there.
A hostile website can easily determine your IP address, even across the Tor network, unless you disable javascript. Law enforcement does operate honeypot sites on Tor to trap users in that (and other) ways. Law enforcement would be mainly concerned with things like large-scale drug dealing, child pornography, etc, and would probably not care about the things that typical users of this site do. But if you are doing other kinds of things, or if you have a real need for privacy, you do need to take precautions.
If you are really paranoid, you should use a live operating system, such as Tails, together with the Tor browser, when you go online. That won't leave any traces at all on your computer after a browsing session (unless you explicitly download files). However it does require more effort.
I have been working with computers since 1971, so do have some knowledge on matters like these.
I have no commercial stake in either of the products I mentioned, but I have used both of them.