My understanding is that no amount of anti-virus software replaces common sense. As long as you're not downloading sketchy programs and giving them permission to run, you're pretty well set.

Some people might tell you that there's no viruses on Linux, but that isn't exactly true. Linux has something like 2% of the desktop market, which makes it less attractive to develop malware for - but 2% of a few billion computers is still millions of potential targets. Not to mention that Linux dominates the server market, and arguably that's where malware is more valuable. To think that there's no malware targeting Linux is naive.

Many anti-virus suites are effectively malware though. If you decide you do need AV software make sure to do your research before installing any.

Anyway, long story, I don't personally use an anti-virus, and for your stated uses I'm not sure I'd recommend one.

If you're mostly using it as a web browser then I would definitely recommend a solid ad blocker. UBlock Origin is free, highly esteemed, and can be installed as an extension to whatever browser you're currently using.