I volunteer at his school: cut, paste, read, nourish, fund-raise, chaperone.

我在宝贝的学校当过志愿者：修建园林、粘贴画报、读书活动、施肥、筹集善款，等等。

youdao

I'm not a director, officer or involved in the day-to-day activities of the organization, but I encouraged the group's creation and help raise money for it as a volunteer.

WSJ: Karl Rove: Dick Durbin, the IRS, and Me

The idea is to raise graduates who see prospects for doing volunteer work, no matter what their major.

FORBES: The Radical Philanthropist

To raise money for our work, I started a volunteer travel company that led hundreds of volunteers on trips to Cambodia.

BBC: Viewpoint: Is gap year volunteering a bad thing?