Headlight/brake light issue

first thing is go through and check and clean all ground wires and obviously check that all bulbs are good and sockets/ connectors are clean and in good shape. once you know you have known good clean grounds check for power on all the non working lights only reason i say to check power is the sockets and connectors can look good but have a broken wire right at the terminal . the headlights could be anything from wiring to the dimmer switch or the headlamp switch itself . the headlamp switch has a built in circuit breaker that can go bad and you will have either no head or tail lights or missing one or the other .
if the dimmer switch goes bad you can bypass it just to test if the headlights work or not . . grounds are the big thing especially on old cars that is usually the source of alot of problems . check back with any news as im pretty good at and love doing electrical work on cars .