It's helpful to learn what types of errors actually happen on coins, otherwise you'll just be staring at every letter and detail questioning whether it's right like one of those "spot the differences" pictures. For example, there's no error I can think of that would make the "T" of LIBERTY look like a 7, so no reason to overthink that one. Also, buying a jeweler's loupe and a USB microscope will be a huge help for you if you don't already have them. The USB scope especially will make posting images a thousand times easier for you.