She went from missing a 6' x 6' backstop to hitting a 10" pie plate at 10 and then 20 yards.
Look out, we got a ringer here! She started out sandbagging and is about to start taking everybody's lunch money in bets!!!
Don't worry about not understanding the written descriptions of how to do a lot of stuff. This is really an "experiential learning process". The written word is great for conveying the science and theory, but the learning happens when eyes, hands, and brains make the three-way connection and you DO!
I am gonna throw my hat in the ring for Sitka spruce. You will find it is far more durable than cedar without gaining a lot of mass/weight. Shooting lightweight bows demands the lightest possible arrows. Sitka and cedar are really the only choices for the draw weight you are working with now. But when you get up to 40 lb draw weights, then you can start considering other materials including ash arrows (brutally strong and durable-but a pain in the ash to keep straight), bamboo (tough to straighten, but you can get super small diameter and amazing strength/durability).
If you really want to get a jump on hunting small game in the bush, look into PatB's beard! Great habitat, but bring a GPS in case you get lost in there!
Here's hoping you enjoy making arrows. They are far cheaper to make than they are to purchase, and if you shoot like me, loosing and breaking becomes absolutely an burning agony.
Good luck, and welcome to the family.