I am a beginner “surviving” with only a bike. As others have said climate plays a big factor. It sounds like there will be few days where that will stop you from riding in AZ but don’t discount it. When it is a 100′ outside and you have to go somewhere and look presentable how are you going to do that on a bike? Also, every time you go out will be into that kind of heat. That will become a real pain in the ass pretty quickly I’m thinking (living in Seattle I have the opposite problem. Rain does not stop me riding but sometimes it just it just sucks).
Since you are at college I will mention alcohol and parties. I would not ride my bike to any party. You may avoid the temptation to have a beer but others probably wont. I avoid riding Friday/Saturday nights as those are the nights most ‘accidents’ happen.
Apart from that, Amazon.com is your friend. I order most large items from there. I have a top box to get groceries but that store also does deliveries if I feel the need to do a large order. I also use zipcar.com if I ever have the need for 4 wheels for a short time. I believe Home Depot rents out trucks by the hour too.