replacing r12 system 88 98 regency

I just cant figure out wich valve is the high and low side so i can finally get some air conditioning in my car

Greetings.Are going to convert your A/C system to R134? If you are,The low pressure fill port would be located near the reicever-dehydrator.It is the can shaped silver object,Located near the firewall.There will be a refridgerant line coming from the compressor to this object.Look for a plastic cap,Then unscrew this cap,There you will see the low pressure fill port.Good luck..Diesel 1962