05 trailblazer ac

my ac pump kicks on and off no matter what the rpms are at. the ac comes out warm and when i try to charge it the pressure goes up to overcharged and then goes to 0 because it kicks off every 10 seconds.

Welcome to AF, you cannot just charge the system without knowing what is in there start with, it should be evacuated, leak tested and properly recharged.

how would i go about evacuating the system myself, do not want to take it into the shop

also my check engine light use to come on and off randomly, now it is on and stays on when i take it in nothing shows and they say i have a blown fuse but after checking all fuses all are good.

If the cel light is on there is a code, now the code reader may not work because the cigar liter/courtesy lite fuse operates the power to the scanner. You cannot evac the a/c without the proper equipment and backround.