Because of widespread fraud committed by con artists who  prey on immigrants using foreign language titles such as “notario  publico,” California has strict restrictions regarding Notaries who wish  to offer consulting services to immigrants, including the following:

A California Notary cannot advertise as both an immigration consultant and a Notary Public.
An immigration consultant may not offer legal advice about a client’s immigration situation.
An immigration consultant may not represent someone before USCIS in  an immigration proceeding. Only a qualified immigration attorney or an  accredited representative of an organization recognized by the federal  government may represent someone before USCIS.
Notaries and  immigration consultants in California are prohibited from advertising  using the Spanish language title “notario” or “notario publico” or other  literal translations of “Notary Public” in other languages.
 Notaries who are not attorneys in California and who advertise in a  language other than English must post a notice in English and any other  language advertised that the Notary is not an attorney and may not give  legal advice about immigration or other legal matters. The Notary must  also post the statutory Notary fee schedule on the notice.
Source:
nationalnotary.org