Don't mean to spoil your excitement.
The real problem is off the north & east coasts, where the reefs have been badly damaged by trash, pollution, runoff, heavy diver pressure & overfishing.
Down south is much nicer, and decent Caribbean diving, which means no thrills & but worth getting wet for. Dive ops largely serve mixed groups with newbies, and this means strict limits on diver freedom & frequent inability to do the more challenging, and to my mind more interesting sites.
The DR is a substantial sized island & you haven't said where you'll be located. If it's north, you can't make southern dive sites on a day trip. If you're west, some dive shops will arrange a day trip south--you'll be bussed down in the early AM.
Do take your golf clubs.
DocVikingo