You might want to open settings and then turn "HTTPS-Only Mode" off. Though if it has been a couple of years since you last tried, it's also not unlikely that most sites will just work now, if that was indeed the culprit.

(Also, if you're the type of person who dials all the privacy protections up to eleven, you might want to hold off on doing that until you've seen everything working just fine, so you know whether those options were the problem.)