How do i know my bridge, eye and temple size?

Go to an optician and ask one of the assistants to measure you. My local optician will do it in return for a small donation to their chosen charity. (They’ll also do minor repair to spectacles in return for a donation).

@Lightlyseared got it. Go to an optician, since they are the only ones who have the tools to take those measurements. Hopefully it wont cost very much.