Not enough info to say.
You need pressure readings from a gauge set with actual numbers, not one of the pitiful red/green range low pressure only things.
If the compressor tries to start then stops, it is probably freon low pressure cutoff working as it should. If so, the question arises as to why it is low.
Normal leakage takes a while, while a larger leak would need repair after locating.
If you want to go cheap, you might try adding freon first with the engine idling to see if that works. Don't use that stop leak crap. A shop won't touch it after that with their expensive machines.
I'd caution without proper diagnosis there is the risk of additional damage due to lack of oil in the system.
One of the kits to add freon might work, I don't know as I have never used one.
edit: If pressure is very low on checking with a gauge set, ideally the system would be evacuated and checked to see if it holds and serviced/repaired as needed with things like a new orifice and accumulator/reciever. Some fairly specialized tools are needed to accomplish this and should be performed by a qualified shop (dependent on your level of experience).