Thanks for using Just Answer. My name is Steve and I will do my best to answer your question.
Here is the procedure for filling your cooling system:
Disconnect heater outlet hose at water pump to bleed air from the system. When coolant begins to flow, reconnect heater hose. Start engine and allow to warm up. Shut engine off and allow system to cool. Remove radiator cap and fill with coolant as needed.
Sometimes I have found that an engine will get very hot (almost inot the red) the the thermostat will open and let the air bubble out and then it will cool normally. You might want to try that...just don't let it get into the red!
I hope this has helped and please let me know if you need anything else