Tokens and how blocking works
Normally, each creature can block only one attacking creature. Some abilities can change this. For example, Brave the Sands has an ability that allows each of your creatures to block an additional creature, and Hundred-Handed One can block a hundred creatures when it is Monstrous.

Without any of those abilities, if you attack with more creatures than your opponent has, then if you attack with everything, some of your creatures will be unblocked and will deal damage to your opponent. For example, if your opponent has 5 untapped creatures and you attack with 7 creatures, they can block any 5 of your attacking creatures, and the other 2 will deal damage.