Check with Down Under Dive shop, whom I've used with good results. Tell them you're new and looking for an "inshore" 2-tank trip. This means 10 miles out and around 70-80'max to the sand with barges and structures that top out at around 60', rather than "offshore" 20 miles out where the Oriskany and Chevron Platforms are, with depths to 100 or even 200' (Oriskany for example) to the sand and top out at around 80-90'.
You want to stay in the "inshore" range (which is also shorter and cheaper since less time and fuel), so just let them know that and they should put you on an inshore trip. Pretty good diving out there, some intentional wrecks and even the bridge rubble, such as the "Roman Ruins" (bridge columns that look like roman numeral II or III) are pretty good too, probably perfect for your experience level, around say 55-75' with decent visibility. the boat is also called the DOWN UNDER. Google 'em and best wishes.