How do I make an entity that fires a laser beam?

I'm making a Fallout mod and I already have many things, but I want to add an assaultron, if you know fallout you know that these robots make meele attacks and once in a while stay still and fire a laser beam, so how do I make a procedure for it to walk and attack normally, and sometimes fire the laser beam, and make damage, and as an extra mayby while shooting the laser beam aming at the player (i'm using blockbench and geckolib also)