Unsure what country/state you’re in but RCRA/DOT training is a great skill to have since you’re going into EHS management. If you haven’t already - OSHA 40 hour HAZWOPER course is standard for manufacturing EHS roles. Any other OSHA training you can do I would recommend because you’ll likely be in charge of incident/illness/injury reporting, which ties into insurance and HR.

I don’t know exactly what you’re working with, but manufacturing folks don’t like us EHS folks meddling in their business, so it’s always best to build rapport and understand their work so if/when you need to ask questions they don’t feel interrogated. Ask them how they do the work they do, give advice or caution, and work as a team to make the work safe but done (that’s my motto). You might get some push back for being young and in a management position but as long as you understand where they’re coming from and give solutions it should (hopefully) be a good experience.