Is there a particular website or way on how does one get started going to the gym?

Like how do I know what to eat, what and how to do each exercise. Reading about gyms only mentions you pay a membership but seems you need a personal trainer to actually learn. I dont want someone watching me all the time and charging me $100/hr for that. I just need someone to help me/somehow set a a routine, teach/learn how to do the exercises once and check back in a couple of weeks once I'm ready to progress to modify the routine if needed.