r22 unit 45 psig low side and 195 psig high side! It runs for about 4 to 5 minutes then the cold freezes and suction line too! Im a first semester student and I'm not sure what to do next!

The first thing I would check is air flow. Lack of air flow--- Dirty evap coil, dirty filter, dirty cups on the blower wheel, blower motor RPM. The 45/195 is low pressure reading. Not knowing the inside and out side temps its hard to say. Then the metering device comes in to play. You didn't say if it was TXV or piston. And then the adage of low on freon.