Once upon a time, I didn't even know about chastity, aside from medieval/comedy devices. I started seeing it in cuckolding porn, but I preferred watching the cuck husbands jerk & squirt. Anyway, years later, perhaps after seeing some amateur porn star wives (or GFs) torture, tease and pleasure their sub-slaves, I decided I wanted to try it out. I'd even seen guys cum in their cages! Anyway, at the adult store I could only find a one-piece chastity tube made of soft plasticy rubber. I bought it anyway, but I couldn't really put it on. It had a ball hole, but it squeezed to tight. I jerked off and inserted my penis in the tube part right as I came. It felt kinda good, but overall I consider that adventure a fail. It was a learning experience, at least.
Welcome and I hope you enjoy the journey and good luck trying to find a device that is comfortable Secure and in you price range.