Having a car available is recommended for this itinerary as the locations are widely spread out. The estimated time on the road will be around 20-30 minutes in between places. Cost of renting a car is approximately $120-200 for three days.
If you have more time, consider visiting other popular attractions such as the Santa Fe Dam Recreation Area or hiking at the San Dimas Canyon. If you have less time, consider skipping the West Covina Farmers Market or Jerry's Wood-Fired Dogs.
The nearest international airport to Baldwin Park is Ontario International Airport (ONT), which is about 27 miles away from the city. Other nearby airports include Burbank Bob Hope Airport (BUR) and Los Angeles International Airport (LAX), which are about 24 miles and 30 miles away respectively.