According to the BC Minor rule, the bats must have "USSSA 1.15 BPF (Bat Performance Factor)" stamp OR "USA" stamp; the maximum length is 32”, the maximum size of the barrel is 2 3/4", and no limit on length/weight drop. The recommended length is from 28" to 30" and the recommended weight drop is from -8 to -12 for most players of this age (rule for 13U is max 32 inch in length, 2 3/4 inch in diameter, -10 max length/weight drop - for your reference if you are planning to use the bat for the next age group).
It is not required but recommended to have your own bat. If you choose to get one please keep in mind that bigger is not better. In fact, a lighter bat can be controlled better and swung harder for greater success at bat.