Can Anyone Help Me?

I've never been very good at keeping flowers alive. I tried to plant a garden in the backyard of our very first apartment in Hawaii and they all promptly died. When we went home for Memorial Day, I was telling my mom that I really wanted some flowers but I didn't know what to get and I really didn't know how to pot them, etc. So she decided that we should buy the flowers, potting soil, and pots at her house and then pot them before we had to drive back to our house. It's like an eight hour drive. So we did and everything looked okay but since I've gotten them back here I just don't think they're doing very well.
They just seem like they are going to die. I had them in a full sun spot but then they were looking so bad that I thought I'd move them more towards are screen door so they wouldn't have as much sun all day long. They were wilty and turning brown. I didn't know that I had to water them EVERY day so I started doing that since they were a little brown. That helped with the wiltiness but they are still turning brown and they have this weird yellowish color to parts of the stems. My mom said maybe I was over watering them so I should just feel the soil and if it doesn't feel moist then water them. So I've been doing that now but it doesn't seem to be helping. I also potted them in Miracle Grow Potting Mix because I figured I needed all the help I could get.And what the heck is up with the one above's spread-out-ness? It was a hanging pot that we just took out and put in this pot. I realize that it's a viney type flower but I wouldn't have thought noting would grow up or in the middle. Is that normal?
On this particular plant the leaves all got the yellow color and then turned brown on the ends and died. What the heck? I don't understand. Is there anyone out there that can give me a suggestion? I really don't want these flowers to die because then I'll never be allowed to "waste" money on flowers again!