You found the right place. "myfwc.com"
FWC is the law of the land. There are many sub-species of grouper and they each have different slot sizes and bag limits. You need to learn what each one looks like before you chance keeping anything. If you happen to keep a Goliath grouper, you'll get arrested, all your gear will ge seized and fined as well, as they are federally protected.
I purchased a handbook when I first moved here 22 years ago that had color pics and detailed descriptions of gulf and southern Atlantic fishes.
I also print out the FWC size and bag limits every 6 months(that's how often they're updated), take it to Office Depot to have it laminated in 3 mil., which waterproofs it, and keep that and the little handbook in my boat/tackle box.
Again, it's up to you, but I highly recommend you learn species and limits. The fines are pretty stiff on out of season, over/undersized, over bag limit. Not just grouper but everything.... Snook, reds, snapper, trout ect...
Keep in mind that there are also different 'zones' each with different regs. Find out which one you're in. (that info is also on the FWC regulations sheet).