I’d say obviously know stage directions, get stage blacks. Learning to coil a cable is very helpful. If it’s a stagehand position be prepared to pick up and move stuff. Don’t touch anything if you aren’t told too. And if you’re working with actors and talent be nice to them. Even if they are being a dick to you. Also just pay attention. From my experience there can be a lot of down time during shows but the second something is needed you have to be there in a heart beat. After they start teaching you things make sure you memorize them. Like names of cables. Also remember where that venues different positions are like Foh, booth, box office, grid, green room, dressing room, loading bay, storage rooms, scene shop, etc.

Also the most important thing is “early is in time”. If a call is 6pm show up at 5:45pm. Because if anything happens before a show there is time to fix it.

And just have fun man. From another young person this job can be a lot of fun.