So I’m making a Kenku wizard for AL, and at 5th level, I want him to have Wall of Water. It is listed in Xanathar’s Guide as a wizard spell, but Kenku is from Volo’s Guide. However, Tritons have Wall of Water in Volo’s guide, so could I give my wizard Wall of Water?
I doubt Tritons are locked out of their Wall of Water in AL rules. It's a built-in part of the race and not an option you're making in character creation or advancement like picking your class's known spells.