What to bring?

The bare minimum requirements for Blood Bowl tournaments are:

Your team. All players should be painted (a minimum of three colours) and all players clearly distinguishable. GW miniatures are not mandatory but if you’re proxying something else, make sure it’s abundantly obvious which players are blitzers/catchers/big uns and not “the Lego guy with the green shoes is my ogre and the Lego guy with a 1 millimetre wide yellow stripe above his left eye is the catcher” Still unsure? Read some guidelines here and remember, Blood Bowl is a game where you should be surprised by your dice, not by your opponent tricking you via the illegibility of their list…
Skill markers to identify any players with additional skills
Dice. You’ll need: two regular six-sided dice, three block dice, one D8, one D16.
Tokens to use as: turn markers, reroll counters, bribes (since any team can receive a bribe on a Get the Ref! kick off result, even if you’re coaching super-honest elves, bring a bribe)
A pen
Several copies of your team roster (at least two)

Nice to bring if you can

A pitch. We usually have at least as many pitches as coaches, but having spares always helps.
The rules (2020 edition and the Death Zone supplement). Most people have a copy of the rules – try to identify yours in some way so you don’t get confused about whose is whose
More dice! More tokens! Nobody can ever have too many dice!
Passing and scatter templates. Mostly unnecessary as many pitches come with these printed on them, but nice to have. As per the rulebooks, make sure you identify yours and don’t get them confused with somebody else’s grey plastic (or paint them!)

More of a note to self than anything else:

Rosters (because a lot of people will forget theirs)
Rules packs (if you’re doing anything more than ‘3 games of Blood Bowl, standard rules, no deviations, go!’)
Prizes & trophies
Extra pitches
Measuring equipment
Computer with Score! and every team loaded in…