Pickleball is an up-and-coming sport and is very big among the older crowd, but is growing among younger people. Pickleball is governed by USA Pickleball USA Pickleball . At this site you can find places to play, how to play and all the up to date rules.
I would like to suggest to just find a place, such as the Chicken and Pickle (No not a food combination) that has lessons and take a lesson to get started. Then start playing...and play some more...and some more. Practice. But supplement that with YouTube videos for beginners and pickleball tips.
Pickleball is a social game...occasionally too social, such as when people stop in the middle of games to talk to other people. Otherwise, just talk to people between matches. Make sure you learn some Pickleball etiquette.
Choose the right paddle. You should start out with a good paddle that is not too expensive. Once you know you're going to stick with it, get a better paddle. I started by Googling "Pickleball paddles for beginners" and found a good, somewhat, cheap paddle. Now I use a Diadem Warrior Paddle. It's a bit pricy, but it is REALLY good and, I feel like it really improved my game.