Here's a good intro.
https://www.muscleandfitness.com/workout-plan/workouts/workout-routines/4-week-beginners-guide-building-stronger-more-muscular-physique/Attached an image of the protocol.
Some people stay with lifting, ending up in a kind of body building. Others branch out into other areas. Some just find a maintenance level and hang onto that.
With age I can imagine gradually reducing total weight as a % of body weight to reduce stress and allow recovery, also making room for othet important life activities.
