All of a sudden my car won't start, so, I charge it for an hour put it back in and was able to start it. I bought a brand new battery but it didn't work. It only work when I charge it.

I had the same issue and it was a grounding problem.
Try running multiple NEW ground wires from the battery to the block and frame.
Also my ground cable from the battery was corroded - replace it.

Check to be sure the battery cable connectors are connected properly and also try cleaning the inside of them with a wire brush so you can see metal shining through. i have had both cable connectors changed on my car because over the years of corrosion they had begun to eat away at the metal and then one day randomly the car wont start or even turn.

Its possible when you put the battery back on after charging, fiddling with the connectors allowed it to get enough spark from the battery.

Just because you bought it new, doesnt mean it was up to par to install in your car. You charging it brought it up to the necessary power levels required to start. It sounds like the alternator is going out. Check the output voltage and amps with a meter. Anything under 12.3 vlts and 200-300amps, and your alternator is no good.