My ac blow out hot air and i want to put freon in my self and want to know how

Adding freon will not correct the problem. If you need to add freon, you have a leak, and you have moisture in the system, the leak should be located, mositure removed, then freon added. But to answer your question. Open the hood on, the left side you will see a round object called a dryer, you will see two pipes coming from it, one at the top and one at the bottom. The smaller is the high side, the larger is the low side. Obtain a can of freon either R-22 or 134a with an adapter for installing the freon. Turn the engine on, turn the AC to high. Add the freon to the ac using the low side.