When a car starts up and you drive it and then wont start up what could be wrong with it?

Hi, I had the same problem with my car just after I bought it. It's an older model with a carby. I was told because of the heat of the engine it makes it harder to start the car after it has been driven at normal operating temperature. You shouldn't have trouble jump starting it, or just give it a lot of gas when you are starting it after driving. If you have a carburettor, you have to be one with it. Hope this helps