I go outside every morning to warm up my car for about 15-20 mins. When I go out to drive my car to school its still pretty cold, but it does warm up abit. But when I go to stop at a stop light it just starts to blow cold air, Then when I start to drive again it starts to get warmer. I dont know what it goin on here but something with the cooling system I'm guessing. Does anyone know what could be wrong?

 

you have an air bubble in the system or you are low on coolant.
fill and bleed the system.
instructions can be found by searching "bleed coolant"

 

If its still cold after that, next suspect is Tstat, cabing flow ctrl - and its vacuum ctrl /brittled rubber hoses...

...see http://www.cardomain.com/ride/748507/8

 

^^^^ +1

I connected a few of those small hoses incorrectly and couldnt get hot air below 35mph. If they crack you could have a similar problem.