AC Help

My wifes 02 Focus isn't blowing cold air. It has worked fine since we got it 2 years ago but this year the AC only blow outside air and he comperssor kicks on like it should when i press the AC button. Where is the high and low side so i can charge the AC and see if that is the problem.

The low side where you would add R134 refrigerant is located at the front passenger wheel
well on accumulator .