Looks like @The Man In Blue and I are pretty close to agreement which is good.
I forgot one thing - a bag to hang on the fence/net and keep water, sunscreen, your spare indicator & pens, keys, wallet, and something to keep your energy up (I like oranges). I have a small igloo backpack which is really good for this.
Now that is an interesting one ... around here that would be a pretty significant faux pas. The only detached thing that should be going to the field with you is a water bottle that can be attached to the fence (preferably out of play).
I would assume that is advice for a multi-game tournament where they aren’t providing you with any facilities.
you can get those plain uniforms at dicks or academy or whatever you have there for 20-25The local league uses USA rules and if I do any tournaments they would be USSSA. I’m in the northern suburbs of Philly. Most likely just night games from April to June but maybe some Saturday or Sunday scrimmages as well. I know the assigner for the rec games and I do not have to be “officially” dressed in USSSA or USA gear. I can wear any of the plain light blue, dark blue, or black umpire polos.