Congratulations!!!
If you're looking for the cheapest accommodations within walking distance, may I suggest the Red Roof Inn Anaheim Maingate? DH and I have stayed there on several occasions and we like it. The rooms are big, bright and clean, and they have a nice pool & spa. Nothing fancy but they are within about an 8-10 minute walking distance and the rooms run about $50-$65 a night depending on when you go.
Hope that helps!