1995 Chevy Tahoe not cooling

You need to check the high and low pressure to determine if it needs freon this is your starting point

Go to the auto parts store and buy you a cheap A/c gage and about 3 cans of freon. Make sure you place the cans of freon in hot water when injecting into the vechicle. Thsi will cause the gas to leave the can faster and do not turn the can upside down. If the A/c beging to cool it has a leak somewhere. If it doesn't cool the compressor may be bad. look and see if the compressor is cycling on a off. If not then try the freon and it should begin to cycle.