Hello my car recently had this ticking noise which wasn't loud at first but when I recently drove it it got a lot louder. I thought maybe the header gasket was bad or one of the plugs was missfiring. I'm only sixteen so bare with me. And also how can I test a miss firing plug. Thanks for the help.

a manifold or header leak can often sound like a tik sound. So can a wrist pin knock (virtually all chevy cavaliers exhibited this sound at one point or another). if you suspect the plug is dead, I've always just figured out which wire, pulled it at the distributor, started it up, and seen if the sound is the same or different. A miss should be pretty obvious, and would more likely sound like a lack of a sound, rather than a tik.