TIme to loose some of your noobiesness
Hows' your tool skills ?
Parts store, 2 gallons of Prestone Anti-freeze, Prestone 7 hour flush.
Grocery store, 2 gallons of Distilled water [not spring water...DISTILLED]
Dealer, pressure cap
Drain cooling system into container and dispose of properly
Refill with water and add the Prestone flush, go drive it for the 7 hours.
Drain the water/cleaner out.
At this point it's a good idea to remove the two hoses that go to the heater core and using the garden hose alternately push water thru the heater core, first one way then the other till all the black gunk stops coming out. Disconnect them up by the front of the motor.
Reconnect the hoses, dump 1 gallon of Prestone in the radiator, then add one gallon of distilled water, dump half of the other gallon of prestone in the empty prestone jug and then use the remaining gallon of distilled water to top of the two half filled containers, result is two 50/50 mix containers of coolant. Now remove the overflow bottle and clean it out good then put it back in, refill the overflow bottle about half way with the 50/50 mix. Start the engine and start topping off the radiator, each time the thermostat opens the level will go down. As you top it off the coolant will look like green fizzy soda, thats air escaping. Each time you add cold coolant the thermostat will close, be patient, when it opens and pulls the level down add coolant. Once it stops pulling coolant down put the cap on, TIGHT. The rest of the air will bleed out thru the overlfow bottle over a few days.
Now in case I missed something the other reason you may not have heat is the fan, does the fan work ? low, med and high or just high speed ? if it only works on high speed then you need to replace the fan motor resistor pack, 10 min job.