The Guardian is a cool looking rocket! Have you never built a rocket before? If not, I can see where that particular one might be daunting. The most difficult part is probably going to be gluing on the 9 balsa wood fins. Not all that difficult, but if it were me, I would have started with a simpler model like the Estes Alpha or Quest Astra 1. They also have balsa wood fins you have to glue on, but there are only three fins. My first rocket when I was 12 was even simpler than that. It was the Estes Alpha III, and it had a plastic fin unit - no gluing of fins at all.
Do you have a friend that has built rockets before that can help you? That would make it easier and more fun.
Jim