over heating

You may need a new thermostat housing. Got to stop the leak. Also you probably didn't purge the cooling system from the air pockets. Cooling system needs to be purged. Check this sight out on how to do this... www.youtube.com/watch?v=xeTgmdRkQtY

Is it expensive?

No it is not expensive.

OK I'm a woman and don't want to be taken advantage of I appreciate your help it's so weird my car ran fine until I let a mechanic do the spark plugs n he never did the wires so it reads misfire 1

And my car is cold the heater doesn't work

The thermostat would take care of the heat. But there are a lot of other reasons for a miss fire, was that taken care of? If you had brought it to a shop for a tune up, depending on what caused the miss, if it was not hard to define, they should have only charged you for the parts. But that is my practice to do.

So the misfire is the reason why my car was shaking in the begging then it started blowing cold when it got cold so I'm just confused bc the prices are outrages

You are risking ruining your engine so I recommend spending the money to have a pro fix the problem.

Yes the miss fire was the cause of the engine shaking. The thermostat would be the problem for heat if you notice the engine not getting to operating temperature.

OK ty so much going to a chevy dealership mechanic

can i use water not anti freeze since its leaking n found out its the coolant temp sensor ordered the part

Yes, just drain it down to get a 50/50 mix back into it once the leak is fixed.

wait what???? lol drain it 50/50?

Your putting water into the cooling system. So when you fix the leak drain the system down so you have anti freeze back in it. A 50/50 mix. 1/2 water, 1/2 anti freeze. This raises the boiling point of the coolant, and prevents rust build up in the cooling system.