Hi and welcome to the forum!
Selecting the right arrow is what will make your bow divine
As for arrow lenght, it would be nice to know your draw lenght! But the thumb rule is, check your draw lenght ad add 2 inches, to get your preferred arrow lenght.
As for arrow spine, check out the goldtip & easton webpages for a spine chart.
there they will tell you how to choose from their chart.
Most likely, you will have to try a size or two or three to make sure it all good, especially as far as weight goes, cause that differes alot from bow to bow, if i have understood it correct :p
As for carbon/aluminum, you will hear defenders of both! I have used them both (abit) but now use only wood. But if i was to stray from wooden arrows, i would go straight to carbon!
And if you get the goldtips, their goldtip traditionals look very woody!