The other guys pretty much covered it and I agree with both. Last year I did two trips. The first to Cancun where I rented everything, and I was very uncomfortable. They gave me snorkel fins instead of scuba fins with a bootie. The BCD was a vest style inflate vs my normal back inflate. Etc.... My second trip to the Bahamas I decided to take everything but tank and weights. Boy was I glad. I was instantly more comfortable and able to better enjoy the dives.
The only two other items I always want my own to bring along is a BRIGHT dive light, and a good camera to record the memories. I’ve bought and sold all of my UK D-cell heavy dive lights in the past. I couldn’t afford the expensive technical can lights. There are many choices, but I really like my Intova Super Nova if you can find them. Brighter than most lights and the rechargeable internal battery lasts through any full day of diving plus some. Any dive, even in full day light is more enjoyable with a good light. You get to peek into all those cracks and crevices. Plus the color you lose at depth really pops. I won’t even get into camera suggestions. There are encyclopedias of opinions on the subject. But my basic peference is for small, durable housing, high MP, strobe a must.
Good luck.