where do i locate the lower ac hose on my car for recharge and what type of refr

i rec you have it charged by a pro as to not damage other parts of the system. it could be either freon depending on if its been converted or not.

How do you know it's low on refrigerant? Can be several causes. Does the compressor come on at all? If not , problem may be electrical. Without guages you may over-charge the system also causing it not to cool