Ac system

You most likely have a leak somewhere. You can put some leak dye detector in or have a shop do a sniff test with a freon detection tool. Obviously likely areas are the hoses and fittings but sometimes the seal on the compressor will leak out which would mean replacement or rebuild.

Where do I get the dye detector ? And once I have It how can I check for leaks with it , or where do I put it to check for leaks , reason being is that I want to learn how to check it and or fix it myself in case in the future I have more issues with it ? Thank you !!