We are an established formwork supplier from overseas. Is there specific license or certification needed in the state of California and federally?
With respect to the construction project your are supplying formwork for, no contractor's license is required as long as no work is being performed on site.
A contractor's license is required in California if you are acting as a "Contractor" as defined by Business and Professions Code section 7026 which includes any person who undertakes to "…construct, alter, repair, add to, subtract from, improve, move, wreck or demolish any building, highway, road, parking facility, railroad, excavation or other structure, project, development or improvement…" A Contractor's license is not required for material suppliers who fabricate materials offsite and merely deliver them.
Certifications required are going to depend on the requirements of specific projects and on who is performing any engineering/design for the formwork.