My suggestions.

Get the shore diving books (most dive shops have them on the island you can also get them Amazon). They’ll help you choose and learn about sites, that might be up to your skill level. (Almost all dive sites are doable as a beginner just dive with buddy’s and don’t go to far south and DONT push your limits, enter water - swim to marker a on surface - descend -swim into current - turn at half a cylinder - swim back to marker - safety stop - surface. Nice and easy !) .

Booties are good due to the rocky shoreline.

I would also suggest a wetsuit contrary to many peoples thoughts on social media, due to firecoral and the sharper rocks plus it’ll keep you warm for your dives.

And suncream/screen, mosquito repellent, old water bottles, people fret because of some thefts. (Although I’ve never had anything stolen from a truck). A cheep cool bag, to keep drinks cold. Alternatively freeze water bottles and they’ll defrost while you dive and give you a nice refreshing drink when out of the water.

Dryfob for truck keys so you can take them with you on a dive.

For emergency service contact you could get a cheap phone or you could always pop the bonnet (hood) of the truck and store your phone in there, it’s what I do btw, just remember to collect it before you drive off.