If it's raining, we meet in the tunnel for the infield. At the morning meeting, we assign who goes to what turns, and we usually try to place newcomers on turns that will get an opportunity to learn about a lot of things. Working turns requires us to be outside all day, so plan accordingly. You'll find a lot of different preferences for white clothing. Some prefer coveralls, some pants and shirts.
Light colors are a LOT better if it's hot.
You'll be standing a lot, so comfortable shoes or boots are a must. Bring along sunscreen, earplugs, a cap and sunglasses. Also, a pair of workgloves, and it's always a good idea to have some raingear handy. You'll find that the longer you stay at this, the more stuff you bring along. You can generally get your vehicle within a few hundred feet of your work station.