It's best to rent a car or use ride-sharing services such as Uber or Lyft to get around El Monte. This will save you time and money compared to public transportation. Expect to spend around $30-40 on total transportation costs.
If you have more time, consider visiting the San Gabriel Mission or the Santa Fe Dam Recreation Area. If you have less time, skip the Farmer's Market and spend more time exploring Whittier Narrows Recreation Area or Arcadia Wilderness Park. And don't forget to bring comfortable walking shoes, sunscreen, and water to stay hydrated throughout the day.