Are you strong? Do you like a challenge? If you think lifting a barbell is hard, imagine doing the same lift with a person. Partner acrobatics for a base is very much like Olympic lifting with a squirming, fidgety weight that makes everything much more challenging.
In partner acrobatics, there is usually a base, flyer, and one or more spotters. The flyer is generally the smaller person that is lifted. The base is the larger, stronger person who remains connected to the ground and moves the flyer through a sequence of interesting shapes. But the most important role is the spotter(s). They keep everyone safe and give feedback to the base and flyer. As important as spotting is, it's not the fun part so we generally rotate roles. However, bases make WAY better spotters. As such, I generally like at least a 2:1 ratio of bases to flyers. Basing at beginner levels is much harder and the learning curve is steeper so I view new bases as an important investment. Spotting is also an art and being a good spotter makes you incredibly valuable in the broader acrobatics community (ie. people are literally trusting you with their lives).
Don't rule yourself out because of flexibility... this is an opportunity to fix that. I have wedges and tools to help get started but bearing a person on your legs will improve your hamstring flexibility pretty quickly. In addition to strength, you will develop a lot more intelligence and control in your movements and build strength in much greater ranges of motion than anything you are likely to do in a weight room.
It's also just a whole lot of fun and a social thing to do with a great group of fit, active people. It's hard work but I generally have a room full of people laughing and smiling. You aren't a showy peacock; you are the muscle making things happen.
Please be at least 175lbs and, if you are that light, have almost all of it be muscle. Bases can definitely get away with a lot more protective padding than flyers but you do need to be significantly strong. Please be capable of doing at least twenty pushups. Please wear comfortable, athletic clothes, be freshly showered, and don't wear cologne / perfume. This is a social activity and you will be touching people and in close contact. Do not come if you are doing this to get a date or be be in close proximity to or to touch hot girls. This is instantly obvious and really wrecks the vibe and erodes trust.
Also check out other Contests in Redmond, Arts events in Redmond.