It will work well. There are several reasons why that will come to be.
The terrain is perfect
When considering the shore dive, which will be your very first dive at CCV, the surface you have to walk on all geared up is hard packed sand, a short 90 staps from the gear-up area to the shore dive entry. From the water to 5' of depth is a sandy path, there you will find something of a picnic table to finish setting up your gear, facemask and all that.
The Front Yard is the dive site that begins immediately after that. NO WALKING from here on out, there's too much life to step on! You are now in a 6 acre area of shallow water that lies shoreside of the wall, basically a swimming pool that maxes out in 15fsw. You could spend the entire day at this depth and environ, I have many times. Lots of stuff to see and- run out of air? No, you'll get hungry first, but if you do suck it dry? Stand up.
Beyond this shore dive entry zone of the Front Yard lies the Channel which holds the Prince Albert Wreck, an intact upright purpose sunk 140' tanker lying nosed into 35' at sand to the stern at 65fsw. She tops out in 22'. You could spend many days just on her alone, again- I have. Get to know her well, it's your best night dive.
To the "left" (East) begins two divergent walls, Coco View and Newmans Wall. The break vertically at heads in 2-25' of water and have a sand shelf at 90fsw. Past that it gets to 3000' pretty quick, so look out and down for Mr. Grey.
All of the dive sites are pretty similar in the same natural design. Moor just offshore in 30fsw over flat reef, just beyond- the wall breaks vertical in 35-40', straight down to that 90' sand shelf. You can dive this any way you wish or the way your physical abilities dictate. In all my many dives at CCV, I have only rarely gone past 65', and that was only at the beckoning of a DM who had found some critter of delight. My usual moored dive profile at CCV results in poking around at the vertical break, rarely going past 50fsw. I'm guessing that my graph would average out to a 25' average over the entire dive.
I have heard comments about "currents", but in 35 years of diving CCV, I really don't recall anything that would qualify- not after 58 years of diving, anyway. You may get some occasional surge, but that is rare and is a basic SCUBA skill that should be mastered by all. At CCV, if you are really so inept as to run low on air, go back and to the boat and play under there at 25', be surprised at what you'll see. (I've seen Oarfish pairs while waiting for the group) If you are doing a shore dive and run short, you need some skills work, but in the mean time, head North. When your head whomps into a rosk, stand up, there will be all the air you need right above you. Anybody that dives the South side deep is missing the point of what this Sun drenched nursery has to offer.
Moored dives are limited to 1 hour so that the human gill-fish don't keep you on the boat for their extra 45 minutes they squeeze out of a tank. On the way home, you can do a Drop Off Dive which is a swim in along Newmans or CCV wall, past the wreck, then right turn (North) into the Front Yard and food.
I mention this in your situation most especially because you can ask the DM to drop you anywhere, either wall (just ask) or whatever crazy distance you want to swim (an "Enduro Dive" is only for the aforementioned "gill people"). Here's the thing for you- let everybody else plop in along the wall, you can ask for a short dive, or what I do- ask to be tossed in right above the Prince Albert Wreck. Dad will find it comfortingly familiar, shallow with a max of 45' of a lot of nosing around looking for critters, or an adventurous look at 65' under the rudder. Then... find the anchor chain and follow it back to... you guessed it- food.
In short, the terrain is commodious for noobs. This should be his 'night dive' opportunity. Do not miss it.
The Infrastructure
Look at the boats and the "wet rooms" (aka lock-less gear lockers). From the exit points to the recovery ladders, these are the best in the business. Where else do you find the center Moon Well ladders? No-slosh camera tanks and boats that theoretically could hold 65 divers that are only loaded with 15-17 max. Fresh water showers and only two steps to make, or a ramp. Also an item of concern for us old codgers.
The entire place is damned near ADA accessible, if you squint, bring a sense of adventure and have a Honduran engineering degree. Entire groups of wheel chair divers do come here, the dinosaurs with canes show up annually for a snorkel only trip. The resort is very compact and very easily used by us gimps. The rooms are all very close-in.
Food is served often and for long periods of time. If your schedule doesn't fit that of the posted schedule, let them know and arrangements will be made for you. I'm operating on 1/2 of a stomach, and this is our first trip back since that surgical adventure.... am I worried about food? Not in the least. I'll let them know, I won't starve.
The dive shop is a separate entity called Dockside. Here's what you should focus on and utilize. Hiring a DM is an interesting thought, but what Dad really needs is a full morning or complete day with Patty Grier. I'd write her and schedule it for Monday. Let him get his flippers wet on Sunday. You'll be doing that shore dive with everybody else, so maybe hire that DM (in advance) for that first day of diving. He will get Dad's gear squared away and get him past the initial jitters. He will be ready on Monday for his smoothing out with a professional Instructor. Patty and her instructor staff are just the best in terms of squaring people away. I sat at her feet and learned the art of teaching and she gave me so many tools that I still use today. I can not recommend any single Dive Instructor more highly.
In summation, go and dive. CCV is an excellent environ for absolute noobs, also for very advanced experts. Those in the middle ground may find it a disappointment because they aren't tripping over larger fish. For Noobs, it's clear, calm, perfect boats, easy shore dive, easy everything. For advanced divers, the insanely high level of micro-macro critters for the Caribbean can not be beat. They are packed into these shallow, Sunlit vertical walls, it is trul;y the nursery of the Caribbean. You can see who the smart divers are- they carry a flashlight and a magnifying glass. The photographers are all shooting macro in the realm of dime sized critters.
It is a place that we've returned to once (or twice) a year for a week (or two) since 1985. We go a lot of places to dive, but CCV is "home".
We will be back 'home' on May 26th for the Full Moon. You?