Welcome aboard! Working on the basis of your location, as judged from a map, and assuming you're interested in becoming a recreational scuba diver, I'll try to cover some basics.
1.) You will need to take a training course and get certified. The mainstream entry level for recreational diving is Open Water Diver. Yes, you'll see 'Discover Scuba' type courses, but they tend to have more restrictions and assume you'll be monitored by a dive professional. What you will likely need to get is the OW cert.
A number of agencies have programs that are used by dive shops and independent instructors to educate, train and certify divers. Likely there's an instructor available near you, and the 2 most common agencies in the U.S. seem to be PADI and SSI.
IIRC, SSI at least used to let people access the academic portion of OW online without paying, I'm not sure how much of it, but my point is, you can use this to learn about scuba diving for free and find out whether it's something you want to do. I haven't read on this in quite awhile, and don't know what PADI is up to.
2.) Beyond that, you will likely eventually want to get the Advanced Open Water cert., not just for some additional supervised training, but because some dive operators restrict the dives and depths they'll take you on if you 'only' have an OW cert., and not an AOW cert.
3.) There is a limited amount of personal gear, such as mask and fins, you'll likely be required to buy for your OW course. You can rent the other scuba gear; some people buy, some rent, don't worry too much about that for now.
4.) Unless you're content diving fresh water places like quarries (note: finding
clear fresh water to dive in can be tough), you'll probably be traveling to dive, at least some. Based on your location, I see that coastal California isn't terribly far away. California has fine diving, and not just boat diving but shore diving. But it is cold water diving, so one needs to wear more exposure protection (e.g.: a thick wet suit). I suspect Cozumel, Belize or Roatan may be of more interest...they have the warm, clear water, coral and tropical fish people associate with scuba diving.
I'll post you some trip reports and research notes in case that helps.
My Research Notes from Planning Cozumel Trip -
My Research Notes from Planning Cozumel Trip
Tres Pelicanos & Casa Mexicana, Cozumel Sept. 2018 Report -
Tres Pelicanos/Casa Mexican Trip Report Sept. 2018
CocoView Resort Trip Report (Roatan) May 2021 -
Trip Report - CocoView Resort May 8-15, 2021
My Notes For Researching My California Dive Trip -
http://www.scubaboard.com/community/threads/my-notes-for-researching-my-california-dive-trip.532316/