Gigi, I started learning about varieties in May 2023. I quickly discovered that there is far, far too much to learn if you try to tackle all different types of coins. Until your eye develops, you won't be able to detect interesting coins even if you have them right in your hand. I have since gone back to my coin pile and found several varieties that I missed earlier.
I enjoy
Jefferson nickels, and now
Kennedy half dollars. That's it. After seven months, I still don't do modern cents, dimes, quarters, dollars, or anything classic. If you try to learn everything immediately, you are just going to overload yourself.
If you want to search coins for treasures, I suggest nickel rolls. There are some more valuable dates that you will find with some frequency. You can learn a lot about mint marks, the full steps designations, and basic grading. You will encounter lots of
Machine Doubling and
Die Deterioration Doubling, and learn what they look like. There are only a few key doubled dies to look for. Most importantly, there are modern doubled dies from 2006-2020 that you can find with some regularity using very basic equipment.