Where can I find excellent cheap home rentals in around San Diego areas in the best areas and how much, help?

I am thinking of moving to California, preferrably San Diego because I hear the weather is great year around there, but I also heard that it is too expensive to live in San Diego. I have never been to California so I don’t know any of the areas there but again I have heard all my life that San Diego has the best weather. You see right now I live in Phoenix Arizona where 6 months of the year it is blazing hot and I hate it. I am originally from New York where the weather was terrible but everything was conveniently located and you didn’t even need a car to get around. In Arizona you need a car to get around to anywhere. Everything isn’t within walking distance and you can’t walk in Arizona. It is just too hot. Anyways that is why I was thinking of moving to San Diego. I prefer where all the shopping and stores are within walking distance. Is it possible to live without a car in San Diego or any other part around San Diego or is a car absolutely necessary in San Diego. You see I don’t drive. I hate driving. How is the public transportation in San Diego? Now if San Diego is expensive, what other areas in or around San Diego is cheaper but have the same weather as San Diego. I love states where it is mostly sunny all the time but not in Arizona where the Sun is too hot. Which areas of San Diego are the best and safest areas with the cheapest rents and how much would that be and for how many bedrooms. Also I prefer spacious houses and also I prefer newer build homes or apartments. I hate houses or homes with stairs because in Arizona most of the houses are one level. Are there areas in San Diego where lets say the supermarkets and shops are within walking distance to one’s home? Which areas would that be? I am not so much into being close to the oceans as in Arizona there are no oceans and I don’t mind, but it is very important that the areas in San Diego be crime free safe and loaded with shops close by. Another bad thing about Arizona is that everything closes by 9 pm. That is too early. Are there areas in San Diego where the shops stay open longer. That is what I love about Vegas but Vegas is hot in the summer too. Let me know all the details. Thanks