I just ordered a test kit from the Ebay. Search "gold test kit" and there will be many to choose from. I bought a kit that tests 10 kt, 14 kt, 18 kt, 22 kt, silver and platinum. The cost was a little over $30 as I remember. I will get it this week so I can send off some of my "Junk" gold and have a good idea of its value. The more experience you have with finding and then handling gold the better you will recognize it without testing. In the beginning or when you are going to send it off to a refiner you do need to have an accurate idea of what you have.
Next, my best advise is hold onto as much of the gold you can afford to. I wish I had more of the rings my wife and I found over the years. The memories are wonderful. Best to you, Mike.