Welcome! Thanks for choosing to be here :) Hope you have fun with your garette and post some good finds this season!
My advice is to get a pinpointer if you dont alrewdg have one its a lifesaver. Practice plugs in the backyard is a good idea. Get a feel for the process.
Detectors have lots of buttons and options for discrimination it can feel overwhelming/confusing at times. Keep it simple! If it beeps when run metal under the head your good to go. If you know how, just turn sensitivity down a little thats all no need to worry about the numbers.
Even if you just find pull tabs and batteries in the yard don't let it discourage you. If you keep at an area of ground over a long period you bit by bit increase likelyhood of finding good stuff by removing all the trash in the ground.
I keep everything I pull out of the ground. Even scraps of aluminum and pull tabs have a spot in my collection. Get a cheap display case or trophy table and show it off!