I was driving to the grocery store I only got a.

I was driving to the grocery store I only got a couple blocks away from my house when the car died I tried to start it it sounded like it wanted to start but it wouldn't turn over I have plenty of gas but it sounded as if I had ran out of gas then I tried to start it and it did nothing not even a noise so I got out and messed with some wires and a few things got back in the car and tried to start it and it started up I turned around and went home and now days later when I try to start it it starts up but the heater is not working my security light has also been on for quite a while I'm afraid to drive it because I'm afraid it might break down on me again what do you think the problem is