Since your coolant was low, it’s possible you still have some air in the cooling system. I would get the cooling system bled of air and see if the problem persists. After bleeding the cooling system, check your coolant regularly. Top it up until your coolant level is at the full line.

They also put my car on the computer at advance auto parts and it just told me something about my coolant system and he told me to buy coolant

Check to make sure you have no leaks in the cooling system. White streaks mean coolant is probably leaking near that location.

It may be worthwhile to do a leak down test. After overheating the vehicle, it is possible there is further engine damage. This could be a blown head gasket, warped heads, or a cracked block. A leak down test will tell you if you are losing compression through the cooling system or some other location.

Have you done an oil pressure test on the vehicle when it reaches that temperature?

I would do a leak down test to see if perhaps it is a head gasket leak.

This is a common symptom of air in the heater core. You could try bleeding the air out of the cooling system, but I would also consider doing a leak down test to confirm if you have a head gasket leak.