It's a pretty slim window between "maybe" and "definitely not"

For example - if it's something simple, like ice buildup on a fan, you could just take all your food out, unplug it for a few days and let the whole thing defrost and then it should work.

But, if the fans work and it's just not getting cold, you will need a technician to look at the refrigerant system. You do not want to mess with AC systems without training.