Alhambra is a small city and easily walkable. However, if you prefer to drive, there are several parking options available. You can also take the Metro Gold Line and get off at the Alhambra Station. A one-way trip costs $1.75, and travel time is around 30 minutes from downtown LA.
If you have more time, consider visiting the Vincent Lugo Park or the Alhambra Historical Society. Alternatively, if you only have half a day, you can skip the Alhambra Park and focus on the other volunteering opportunities. Remember to wear comfortable shoes and clothes, as you'll be spending a lot of time outside.
The closest airport to Alhambra is the Bob Hope Airport (BUR), located in Burbank, about 20 miles away from the city center. However, most visitors prefer to use the Los Angeles International Airport (LAX), which is the largest and busiest airport in the region. LAX is about 30 miles away from Alhambra.