My vote is the Y. I’m middle aged and not that fit but do go to 3-4 classes a week to stay active. I bounced around to 3-4 different Y’s because I workout while my kids are practicing their sports in the evening. While there are a few fitter people at the Y generally it’s a very low key wholesome organization. I’ve never felt intimidated there. For reference I tried ACAC and it was intimidating and pretty upscale (snooty?) for my needs. For sure I gravitate towards certain classes that “meet you where you are” vs the boot campy type classes. But for sure you will find a few you really like if you are willing to try new things. Good luck. DM me if you want some class examples.