I am installing a new thermostat to a 4 wire connection and have no clue where they go, I have a red, white, blue and green wire.

Red is probably from transformer, white may be heat, blue to compressor contactor coil for cool, and green for the blower fan.
Try red to r, white to w, green to g and blue to(verify with instructions) b? Or Y?

Read the install instructions that came with the thermostat?

Brand and EXACT model number of the stat you are trying to wire?