"I would like VFR flight following. Can I request that before departing my non-towered airport? " - Ed P.
“Generally No. This is not a good idea for several reasons. There may be some local procedures that are different at other airports, but your focus on departing a non- towered airport should be on the Common Traffic Advisory Frequency and local traffic. Once you are safely clear of the pattern, then you can contact ATC for Flight Following.
Some special procedures may apply in the certain areas – such as the SFRA, or Special Flight Rules Area around the Washington DC. Special training is also required to operate in these areas. Be careful!
ATC is reluctant to give a code to a VFR aircraft that they are not in direct contact with. If you have a change of plans for example a rough mag, open door, etc. that delays or cancels your flight they will be looking for you and may have to initiate Search And Rescue.
At a Towered airport, the tower controller is in direct contact with the approach controller, so if you have a change of plans, it can be instantly communicated.”