I was in your exact position bro, I would go to the gym now for sure; you increase your metabolism and start building muscle. Start with the 5x5 program, you can find it on stronglifts.com it is very simple, you do squats, bench and deadlift and some side work such as bicep curls and shoulder press. Just make sure you dont feel embarrassed to ask for help with your form at first, I regret not doing that lol