Gotcha. Look into the books already mentioned. Also, there's a few great arborists on YouTube that have really good technique to replicate. Climbing arborist, august hunicke, buckin billy ray, and Human, to name a few. Climbing arborist goes into really good detail on climbing systems and all the parts needed.
I'd recommend doubled rope technique. It can be as simple as one rope and your harness, tied in a closed system with a Blake's hitch. (Tie the Blake's wrong and you'll know). Along with your primary climb line you'll need a lanyard/flipline, when you need to advance your primary you get tied in with your lanyard. ALWAYS be tied in.
You'll learn the climbing fast. The thing I'd study and practice would be the dynamics of cutting. Compression and tension, lean of a tree, how to notch and back cut, will this branch swing and hit me? or snag my rope and pull me out? There's a lot to learn but you'll get it in no time.
Good luck!