As an oddity, no. '84-P quarters typically have illegible mint marks. Generally unless it looks like "D" then it's a "P". It's actually one of the better '84-P's still in circulation. Most of these are scratched up because of the low rims for the date and they have much more wear. This is a poorly made VF but there are still a few well made XF's out there.
Very Fine, Extra Fine. Both are grades of coins. If you have a R.S. Yeoman Red Book it will explain the grades in more detail. If not, best to buy one but done go by the prices. It’s just a guide. D with a hit is a D or Denver Mint mark. The mint mark took a hit as in something struck the D and made it look different. That would be damaged.