From the 5 freeway, take Ortega Highway east, turn right on Via Cordova.  It will dead end on Calle Arroyo.  Turn left and you'll see the park on the right. 

Field 1 is the eastern most field and is typically used for 14U and 12U, Field 2 is in the middle and is usually used for 10U, and Field 3 is on the western side and usually used for 8U.