Unwanted pop ups and advertisements

You could avoid the websites where you encounter the worst swarm of flies (click bait), as the web site adminstrators are more interested in earning money from those hosted ads, than protecting you from the inherent scams, and malware that may arise.

For ad/malware that has found its way onto your Mac, and that may be altering your browser experience, I suggest running the free Malwarebytes for Mac to see if it detects any of this junk and offers to remove it.

Okay, Chrome is not well respected on these forums due to it being such a RAM hog. However you should look for it's settings to see if there is a popup add blocker. I don't use Chrome so I cannot tell you where to look.

What browser do you use?