You don't need to bring your own cards or deck to participate in a booster draft. Just turn up and play!
In a booster draft, each player is given 3 booster packs which they will pick cards from (draft) to build a deck. You keep the cards you draft.
Before the draft begins, it's a good idea to get familiar with what each hero and their weapon does.
For your first draft it's recommended you choose your favorite hero, and whenever possible pick a card of that hero's class, otherwise pick a generic card.
The first thing each player should do when they open a booster pack during the draft, is remove the token card and throw it into the middle of the table.
You need to build a 30 card minimum deck from the cards you draft.
You don't draft hero or weapon cards. You add these to your deck after the draft has finished, usually from the tokens players have collectively thrown into middle of the table (see point 5), or provided by the tournament organiser.
Young hero cards are used for booster draft games.
If you want equipment cards, you'll need to pick these during the draft. It's normal to play draft games with less than a full set of equipment.
Just like constructed formats, your hero dictates what cards you can play with. Cards in your deck must be the same class as your hero or be generic cards.
You can have any number of copies of a card in your deck. If you draft 5 copies of the same card, you can put them all in your deck.
Official booster draft matches are 30 minutes, best of 1.
Have a way to keep track of your life total, such as pen and paper.
Deck boxes, sleeves and play mats are commonly used to protect your cards, but are not required.
Store judges/staff are there to help, so if you have questions about rules or the event itself, make sure to ask them. This includes during a game.
If you want to play in an official Booster Draft event, you'll need a GEM player ID. You can get that here.