We're not in Fairfax Co, but Child Find can look like lots of different things depending on your child's needs and the ISP that's developed. Child Find is really just the wide term for special needs services for the 3 - 5 age group. It could mean going to the county preschool, it could me individual services through a county therapist at your house or your child's private preschool, or it could mean group services at a county location, but not full time preschool (ie, group speech therapy or OT once a week)
What are you receiving services for on your Infants and Toddlers IFSP? The needs shouldn't be all that different between your I&T IFSP and the Child Find ISP, although the method of delivery may be very different. Your current Infants and Toddlers provider should be working with you and with Child Find on a transition plan.