If it is pistol matches you are looking at I suggest IDPA. It is as user friendly as any of the national based sports. Equipment is not critical & there are lots of folks who don't take the completion very seriously. It will give you a reason to improve your skills and meet new people.
I have to agree. I shoot USPSA, IDPA, and ICORE. I believe IDPA is the easiest introduction to the action pistol sports because of the limits they place on gear and the designs of the stages. All you need to start is a reliable self-defense type gun, three mags or three speedloaders, a holster, and a carrier for your reloads.
I do advocate taking an "Intro to" course if one is available near you. Nearly everybody fails to realize the stress that the timer and thoughts of an audience puts on you, and can often cause lapses in a focus on safety when moving or reloading.
And whether you take a course or not, I encourage you to do everything during your first match in slow motion. Nobody is going to bag on you for being slow, but you will become quickly unwelcome if you out of control and unsafe. So go slow. Then do it again next match. And the match after. And when you feel like safety is ingrained as the primary instinct, then try going a little faster.
Most people find that shooting competition is a great activity, even if you don't win. You'll find a tremendous satisfaction is you become more instinctively competent with your gun. Draws, reloads, sight acquisition, target transitions, malfunction recoveries...all skills that get honed by the action shooting sports.
There are downsides. You'll spend a lot more of your disposable income on ammo. You'll have a harder time enjoying the slow-fire pace of public ranges. Definitely worth the costs, to me.