You shouldn't drive a K1500 Chevy pickup, or any vehicle, very far with low transmission fluid. Driving with low transmission fluid can cause significant damage to the transmission, potentially leading to very expensive repairs or even a complete transmission failure. Even a short distance could cause irreparable harm.
Instead of trying to determine how far you can drive it, add transmission fluid immediately. If you're unsure how to check the fluid level or add fluid safely, consult your owner's manual or take your truck to a qualified mechanic. Driving with low transmission fluid is a serious risk.