I want to get back into a workout routine but don't know where to start. Back in my senior year of high school, almost four years ago, I worked out 3-5 times a week consistently at Planet Fitness. I worked out with a friend who helped set my routines. I know Planet Fitness is controversial on this sub, and I might not have been doing the most effective workout possible, but I was starting to see gains. I did this consistently for about nine months until I started college and got really busy got very lazy. I also had a bad falling out with this friend so I'm on my own now for developing a workout routine.

Fast forward to today, I want to reestablish a workout routine. I'm a commuter student at a state school, and there is a good campus gym that is already included with my tuition. For reference, I'm 20 years old at 5'10" (1.78m) and weigh 155lb (70.3kg). My main objective is to build more muscle tone. I'm in decent shape now, but I'm thin and don't have enough muscle. If anyone has any advice or could lead me to any good resources for a beginner developing a new workout routine, I would greatly appreciate it.