Lots of good advice so far. I wish somebody had mentioned kneepads to me about 20 years ago. You don't need to carry as many tools with you as you think, your back will thank you as you get older. Find your older guys and talk to them. I have learned way more from older mentors than any class I had in tech school. Not everyone will be interested in teaching you but the ones that are will be a wealth of knowledge for you. Keep up with current trends in the industry. DDC controls and freq drives are great but realize there are still plenty of built up systems with pneumatics in service because they run even when neglected. Listen more than you talk. Good luck.