I would recommend starting with something basic if you are not sure what your long term dive goals are. Something inexpensive and not gas integrated is a nice start to get used to using a computer without a huge investment. Then, if you really step up your dive game in the future, you can buy a fancier computer that does everything you could ever want (whether that be multiple gasses, air integration, or both, OLED display, games to play during long deco, etc.), and your first computer is now your backup computer or set to bottom timer mode it can be your backup time source and depth indicator.
Here’s what I did: Bought a DR Nitek DUO 10 years ago. Ran that as my primary for several years with analog gauge and watch for backup. Then I got a Nitek TRIO (3 gas) for deco diving with back gas and 2 deco mixes. I managed to lose that one out the back of my truck a couple years ago, so I then got a NitekQ with 7 gas Trimix capability and OLED display to see easily in low light. The original DUO remained my backup through all this (run in gauge mode). I recently picked up a second Nitek Q to be my secondary computer for trimix dives, but that good ald DUO is still my go to computer for shallow recreational dives. Keepin it simple and familiar.
I’ve seen a lot of divers lately with Shearwater gas integrated computers costing upwards of $1500, even though they only do shallow recreational dives on air or nitrox and are fairly new to diving. I feel this is not a wise move, as I spent less than that for all the computers I’ve ever had combined. I suggest waiting until just before you need the advanced features before buying the fancy computer you won’t have something whose features are obsolete by the time you go to use them (i.e. technology continues to improve, so the 2024 model will be better than what you buy in 2019). Same reason I have two $800 dry suits and 4 sets of $50 underwear instead of one $2000 suit and some $300 underwear. If something breaks, I’m not SOL and I spent less than the guy that bought the top of the line.