Just go to the gym
Be friendly, polite, and ask somebody to show you.
Develop the mindset that you will work very hard. People will see it, and reach out to help you. Try to do 30 minutes of "cardio" daily, sufficient to breathe deeply, pushing yourself as much as you can. For each muscle group, 3 sets of 10 reps of a manageable weight 3x/week, increase as your strength grows. You'll see results & meet great people.