HEY MOOSE!!
Just keep doing what you are doing. Soon, you will be able to tell that some targets are very big, and the difference in the small dense targets like coins. You are doing fine, just listen to the machine, and after digging the target try to remember the sound it gave.
We all dig trash, some days alot, some days a little. Some machines pick out the preferred signals better than others. Remember that it depends what you are looking for and where.
A relic hunter in a nice smooth plowed field will likely dig everything. But if you are coin shooting in a park, you will probably be more selective since we do not want the park to look like gophers attacked it.
Look forward to more finds from you!
Bob