Catalina's Casino Point won't eat anyone's lunch....it won't even nibble your crackers! If you simply stop by ScubaLuv or Catalina Divers Supply, you can get a nice instructor to guide you for a couple dives. If you make it thru a couple guided dives, you can evaluate if you are able to handle the rest yourselves. There are so many rescue certified divers hanging out there that your only real danger on a busy summer day is being rescued by accident! You may even be able to find a nice couple to buddy with when you have your finning legs back.
If you stay on land, you can also enjoy hiking, Kayaking, dancing by night, and many other nice "dating" activities. If the live aboard sounds more attractive, get some refresher action ahead of time as DMs don't really guide underwater on these boats.