The AC side fittings are generally SAE 45 degree flare for 1/4" tubing. ( not inverted flare brake tube ) Any decent auto parts or home center will have something.

As for the regulator side, most use a male thread ball seat fitting that I can't recall the name of. A welding supply should have this. If your regulator has a hose barb with a clamp, attach a piece of at least 100 PSI working pressure hose. ( Fuel injection hose , Gates Lock On type hose works also. )