I got certified last summer and bought all of my gear within a month after getting home from my trip. So far, I have only upgraded two things: my computer and my fins. The fins I bought at first are awesome, absolutely nothing wrong with them. I, however, changed. As I learned more, I changed my preferred kicking style and just didn't feel like I was very efficient in my first fins. I also learned more about my body's natural buoyancy and decided heavier fins would help with my trim. I won a computer upgrade in a raffle, but misplacing my original and the new one prompted me to just jump in and get what I really wanted in the first place.
I say all that because I used to scoff at being told "try gear first" and now, I get it. I swore I'd never have any interest in a backplate and wing (it looks SO uncomfy)....but now what am I looking at and considering? I love my BC, and have zero regrets in the one I purchased, but I keep wondering if I should have looked more seriously into the bp/w option a year ago before I spent money.
My regs? Love them. Zero regrets. I did a TON of research and found a brand I liked that has quality gear at decent prices...and they are sold and serviced near me.
Sorry this is so long, but you are about to embark on an expensive journey. Your gear purchases are never done, haha. I strongly recommend renting everything but mask, snorkel, fins, and possibly an entry level computer. Try different brands and styles and do a lot of homework before you buy expensive gear. This stuff keeps you alive under water so while you don't need the most expensive things, you want to make sure you get what will work for you.
Good luck and enjoy the journey!