Sorry if I missed something, but it seems like I can't import or open this in GM [from the outside, it looks like GM doesn't recognize this YYZ file type, but again I could just have missed something]?
Hello. Were you able to find and watch the YouTube Tutorial series? It's linked several times in the main page and should be easy to find. If you can't figure it out, please consider joining the Discord where we have an active community that will be more than happy to help you, including myself if I'm available.