I would book tickets when you arrive in USA! Or would book online through they Disneyland site. Don't book them through here as agents have a nice mark up!

Accommodation vrbo is fab we have used it heaps but if you stay in a hotel they have free shuttle buses to most places you will want to go close nearby in Anaheim. So factor in the cost if taxi etc to your vrbo rental! Have fun and enjoy being their in their off peak season!