I get cool air instead of heat at all time no matter how far you drive it
If coolant isn’t traveling through the heater core properly or there is a clog somewhere in the tubing, this could cause cold air to blow. If the thermostat is working properly and your coolant level is correct, it could be the heater core that is preventing warm air to blow through your vents
Or your blend door actuator has failed.
I’d say check heater hoses. But others might say that. Again.
If you hear a gentle click click click from under the dashboard, your blend door actuator failed. And auto repair shop can diagnose and replace this electric motor and gearbox assembly. The part is less than $100 but the labor to replace it might be significant. Common problem on GM products.
Is your coolant at the correct level?
If the coolant hoses which go through the firewall to the heater are easily accessed from engine compartment, turn heat on max, then carefully feel both hoses after the engine has warmed up. If both feel pretty hot, heat from engine coolant is likely flowing through heater matrix ok, so problem is the heated air isn’t getting to the passenger compartment, hvac door or blower problem. If one hose feels hot and the other not, something is preventing heated coolant from the engine from flowing through the heater, faulty valve or valve control, or plugged heater (possibly just from air bubble).