Each child chooses to be involved - it's not chosen for them. As a Big Friend, you are not expected to lavish the child with gifts, or be a constant source of entertainment. The simpler the time spent, the better. The child needs, more than anything, someone who will be willing to listen, and cares enough to be there for them consistently. Your caseworker will also call regularly, but don't hesitate to call if you need support.
Training is provided as well.
If your work demands are unpredictable, then maybe this is not the right volunteer experience for you now. We do however have a wide range of volunteer opportunities that might better suit your schedule. Each match is as different as the people involved. Some continue for years, for others the year is sufficient. Every six months the volunteer, child, parent and caseworker discuss the goals and time frame of the match.