The 3 parts of music theory grade 1 are here:

Part 1
Part 2
Part 3

Part 4 should be coming along soon and then we'll be on to grade 2, so subscribe to the newsletter to make sure you don't miss any :). Many players don't read a note of music, or understand particularly what's going on... and in many cases they don't find that a limitation. But, I think the theory side can really help your playing, and if you're going to be a musician you might as well speak the language.

If once you've read the three pieces you have any questions, please feel free to PM me.