I need help

I need help. I don't understand how cellphones work. And, I'm breaking down and buying one of the stupid things. Why, you ask? Because in two weeks, I will be homeless. I will need a "place" for people to reach me. Where will that place be? My cellphone.
I just got off the phone with Rogers. I loathe Rogers. They spoke to me of 1 to 3-year contracts. I told them I didn't want to be in any contract with Rogers for more than a year. So, as I understand it, there is 1) the contract, and 2) the plan. I asked what the contract gave me, and, as I understood it, it gives me nothing but the privilege of using Rogers. The plans are too complicated for me to even begin to understand. I just want a phone I can use with a fun ring tone. For me, that will be the only good thing about this new purchase. I'm thinking a BeeGees ring tone.
Help. Please, someone, explain cell phones to me, and how I can get a fun ring tone.