What are my chances of having a vbac since my first pregnancy was c section?

Usual practice: By most authorities would be to proceed with a VBAC under these circumstances unless an issue has come up requiring c section although this varies from country to country and the VBAC would need to be done in hospital so a c section can be done rapidly if complications/fails. For specifics for your situation and risks please consult an obstetrician or maternity carer.