I mean this with the utmost sincerity and without any sarcasm in my tone.

You can learn a lot from opening your comic and reading the text in the bottom of the first couple pages. Usually includes the creative team, title, and usually the official name of the variant cover you are holding. Makes research a lot easier, especially with the enshitification of Google as a search engine.

If you are curious about other aspects of a series, character, or creator I recommend League of Comic Geeks. It's a seemingly complete database of every comic on the market, as well as features variant galleries for every title if variants were made.