I turned it on and I felt cool air for a split second then immediately hot

Hi guys, I've had this truck since mid march and recently I thought I'd try and see how the A/C did, so I turned it on and I felt cool air for a split second then immediately hot, so I checked the fuses and the one for the A/C clutch was missing so I put one in it, tried it again got cool air for another split second then just warm air, not as hot as last time but still not even close. So I'm guessing maybe I should check the pressure in the system and see if it needs recharge? I've rarely ever worked on A/C systems before, I've recharged a few systems before but nothing major. If it turns out that the system is fully charged what would I need to do from there? I tried Googling diagnostics for A/C systems but every answer pretty much ends with going to a certified tech, I mean I could go to one but it'd be nice if I could save some money, especially if it's something small or simple.