What could be wrong with my car?

I'm a 21 year old girl who knows NOTHING about cars...except how to put gas in!i just got it rom my uncle who said he's never had problems with it. It's a 2001 Ford Taurus SE.
1. In the winter my car would warm up really quick and the air would get super hot! But lately I noticed it hasn't. The other morning I had turned it on for 10 minutes so that it could warm up since there was ice on it. When I got in my car after 10 minutes it still wasn't hot. It was barely getting a little warm air. After driving for a bit some warm air came out but it was barely even warm.
2.The little thing that's next to where you MPH is...there's little thing(sorry idk what to call it) that says C for Cold and H for Hot.My cousins noticed last night that it was all the way up to the H after only having driven it for 5 minutes.
I think they mentioned it was the radiator. Are they right?If so, how much will it typically cost to fix??

thebax20062015-03-24T06:06:24Z

Fill the radiator with a 50/50 mix of antifreeze. Don't drive the vehicle before putting antifreeze in the cooling system or you'll ruin the head gaskets and have a $2,000 repair bill. Then drive straight to a repair shop and have them pressure test the cooling system so you find out where the coolant leak is coming from. if the water pump is leaking you might not make it to the mechanic. Once you fill the cooling system you need to run the motor for 15 minutes with the radiator cap removed so that you get the air out of the cooling system. After you get the air out and top up the radiator put the radiator cap back on and run the motor another 10 minutes. if you have antifreeze dripping under the car by the right front tire have the car towed to a mechanic because it's likely a bad water pump and you will overheat the motor before you get to the repair shop driving.

Tony2015-03-23T23:19:21Z

A radiator job can be a few hundred. Take it to someone to have it looked at first, it might not be the radiator. It could be something as simple as a stuck closed thermostat.

If you do decide to take your car to someone, keep an eye on your gauges. Your coolant, the one you're taking about next to your speedometer, should remain in the middle or below to be safe, it should move from the c (cold) to the middle and go no more, if it goes above the middle, pull over, shut the car off and open the hood to allow it to cool, once the car has cooled, continue driving and keep an eye on your gauges, do that until you reach your mechanic.

?2015-03-23T23:50:55Z

You are low on water, that is why your heater stopped working also why your engine over heated.
You are low on water, put some water in your radiator.
Stop driving your car when the gauge tells you is over heated.
If you kepp you doing that you will ruin your engine when all you needed to do was check the water and put water in it. Your friend obviously knows nothing about cars.

?2015-03-23T23:38:00Z

You are probably just low on coolant.
First thing I would do is check the coolant level and fill it up with a 50/50 mixture.
If the coolant level is low you probably have a leak somewhere.