The elusive trime. Well, elusive to me because I've never found one. Plenty of half dimes but never a trime. That's a hard one to get. Congratulations.
metal detecting is fun and finding cool old coins is one of the things that makes it a fun hobby. I got interesting in detecting primarily because of my love of history and a love of coin collecting. Read up and learn the history behind the coins and other items you might find. It helps keep your interest peaked and a little extra knowledge never hurt anyone. Here's a page of the history of your coin.... https://en.wikipedia.org/wiki/Three-cent_silver