Kinda a noob question. So i just got a Randall rh150 g3 head and it has a line out port on the back panel. does this allow me to record directly to an audio interface with it by using a cable to connect the head from to line out to the audio interface or is the line out used for something else. I dont have a cab yet but i want to try the head out and see if everything seems to work and sound good (i got it off ebay)

Pretty much, but it shan't sound as good as it would running through proper speakers.
Indie Custom Guitar w/BKP Nailbombs
Blackstar Series One 100 Head + Cab
MXR Phase 90
MXR carbon copy
TC Electronics Polytune
Dunlop Crybaby Wah
Make sure you have a cab plugged in whenever the amp is on, to avoid damaging the amp.
Epiphone SG-400 (w/Hot Slags)/Chapman Guitars ML1 > Digitech Bad Monkey > Blackstar HT-5 > Danelectro Fish and Chips EQ > ETI Chorus Flanger
Snark Headstock tuner!