On this forum, I think you’ll find there’s no silly questions. Just questions.. and some vulnerability, which we all respect and appreciate.
Essentially cockrings just provide pressure around your penis or around your penis AND scrotum and help retain the blood and so hopefully maintain your erection. Results vary and there can be whole discussions on material, size, usage, weight etc. and theres been a number of posts about them you might find useful. As starting points ..