CVD, if you really don't know about AC systems, do like Doug said and take it to a professional. And, I can recommend a perfect place that fixed ours.
Go to Redlands Performance and RV service in Redlands, CA. They are the best. Do not go to Colton Truck Terminal in Colton, they tried 3 times to play with my AC system charging me each time and no fix.
Redlands Performance and RV Service fixed my AC system the first time and it has been ice cold for 2.5 yrs. now. They are my go-to people and have done other things for me including new hoses and other minor repairs/maintenance. They installed the new air brake system on my new Honda. They have never had to redo anything they have fixed. I'm sure it happens, but they are good and will stand behind their work.
Don't throw money at your AC, get it fixed right.
Good luck,
MM.