If you're completely clueless, I would join a gym with a range of machines. Machines are great, because they are low skill, you don't have to talk with anyone o

If you're completely clueless, I would join a gym with a range of machines. Machines are great, because they are low skill, you don't have to talk with anyone or feel embarrassed if you're not doing an exercise correctly. Level 0: Write down some goals you want to accomplish. For me, I want to do 15 pull ups without a rest. But it could be run a mile in under 8 minutes. Write down when and how often you will be going to the gym. Hold yourself to this. Put this list in a place you will see it often. Level 1: At the machine, sit down, look at the picture, do the the motion (at a light weight) 10 times. Move onto the next machine. If you have questions about how to use a machine, ask the staff. Here, you are forming the habit of going to the gym. Don't worry about pushing yourself. Just focus on going to the gym 3 times per week. as u/jhauris said, keep things as friction-less as possible. Level 2: After a couple weeks of level 1, start doing multiple sets at each machine. Do the motion 10 times, rest for 1-2 minutes, do it again. repeat 3x. Stay in the gym exercising for at least 60 minutes. Level 3: After 2+ months of this, you can add cardio before your workout. If you have a bad back, try the bike machines or stepping machines. Many gyms offer classes which can be fun and motivating as well. Level 4: You will start noticing your weights are not improving as fast as they used to. Up to this point, you have been doing a full body workout each time you're at the gym. You should try to shift into using the free weights with a focus on different muscle groups per day. Monday: Legs; Wed: Back and biceps; Friday: Chest, shoulders, and triceps