You're in the same position I found myself about a year ago. I've really been enjoying it since then. I won't offer any advise on skills but I'll let you know the basics of starting.
Check out
http://findshootingmatches.com A local USPSA guy put the calendar on there and you can see when all the local matches are including steel challenge, USPSA, three gun etc. Next USPSA is next Sunday at Paul Bunyan in Puyallup. Renton Fish and Game is 4th Sunday. I'm pretty sure Black Diamond does it Thursday nights but I have not tried that one.
You need a safety check before they will allow you to shoot. If you know what match you want to go to you can generally set up a safety check before it starts or separately a day or 2 before. If you wanted to do Paul Bunyan next weekend they should be able to give you a check Friday afternoon or at 9 am before the match starts. Safety checks need to pre coordinated. If you know your timeline when you want to shoot I could help find you a check.
If you are shooting steel halfway proficiently, I would just go straight into shooting a match. Just take it slow and enjoy it. Everyone is there to help regardless of if your a grandmaster or a beginner. Just be safe and willing to learn. You can start off with as little equipment as a belt, holster, and 3-4 magazines. More if shooting single stack or revolver. I wouldn't buy a ton of stuff until you shoot a few and see what works for others.
Do you have an idea of what class you want to shoot, Production, limited, open etc? Some of these depend on the mods made to the gun or wether it is stock.
I will be shooting Paul Bunyan next weekend so if you want to drive down to Puyallup to see it, let me know. We can arrange a safety check.
If you are a Facebook guy "USPSA-Washington State Shooters" is where a lot of local stuff gets put out.