I used type F transmission fluid in my GMC sierra 1500, will everything be okay?

These systems can hold about three gallons, so if you didn't put in more than a quart you can probably get away without any trouble. You see, "F" type fluid is for Ford vehicles, and your GMC requires Dexron III or IV. I honestly don't think there is much difference. So an easy remedy is to slip a suction hose down the dipstick tube and vacuum out what you can.....about five quarts. Then top it off with the same amount of Dexron. This will dilute your mistake and be like a partial fluid change. Run it and recheck the level. I've done bad things to vehicles and they still survived, so not to worry. I hope this works for you.

Drain it or flush! You cannot use the wrong fluid in a modern car.

The reason I am not panicked about that error is that my Dad was a Chemical Engineer for Quaker State and he always said that all oils start with 95% Neutral Stock, that's like mineral oil. The other 5% was merely a blend of dyes, detergents, antioxidants, stabilizers, and viscosity improvers. So this error really amounts to only a few ounces. Nothing left the refinery without his approval. I wanted to keep my answer simple but I too have a degree in chemistry.