@Kevin Nguyen,
Personally, vacation time is uber valuable and I would advise reserving that time for fun diving.
If you are considering diving in your local area, I would recommend taking your open water certification course locally. I would also recommend taking the course in a dry suit, as too many students suffer in thick wetsuits in their courses. Some people who have a tolerance for cold will disagree, but when I taught at a shop that primarily taught in wetsuits in the Puget Sound, most students were miserable after the first dive (and comfort management was a high priority). You don't need a dry suit certification, just an orientation.
But if the idea of getting into the cold water horrifies you, then do so in the tropics. Diving is supposed to be fun and that includes courses.
Of course, the most important thing is to find a good instructor that matches you, as teaching styles vary, and what works for you doesn't necessarily work for other students. I'd highly recommend reading Jim Lapenta's book that can be found here:
SCUBA: A Practical Guide for the New Diver: James A Lapenta: 9781494900250: Amazon.com: Books to help you interview prospective instructors.
In addition, I'd recommend finding an instructor who is adamant about proper weighting and buoyancy. Some of the notes I have written here:
Thavmas Scuba may be useful to you. If you read the 2016 DAN report (
https://www.diversalertnetwork.org/medical/report/AnnualDivingReport-2016Edition.pdf) on page 5 you'll see:
Ten Most Wanted Improvements in Scuba
Correct Weighting
Greater Buoyancy Control
More Attention to Gas Planning
Better Ascent Rate Control
Increased Use of Checklists
Fewer Equalizing Injuries
Improved Cardiovascular Health in Divers
Diving More Often (or more pre-trip Refresher Training)
Greater Attention to Diving Within Limits
Fewer Equipment Issues / Improved Maintenance
All of these should be covered thoroughly in your open water course. Talk to prospective instructors about this list and how they address it. This came out 3 years ago, so good instructors will have adapted by now if needed.
For the third one, I've attached my dive planning doc that I use in teaching in my local area. The topic of gas planning may be useful for you.
Whatever you decide, good luck!