I currently do not have a training certificate in ‘Working in Partnership with Parents- The Parent Advisor Model. I understand how The Family Partnership Model assists the family health nurse to guide and support families within the community. My understanding is that the Family health nurse’s works in partnership with families to provide family centred care and build on strengths within the family, promoting parenting confidence and building on what the family does well rather than having an authoritarian approach. I also understand that some families are more vulnerable than others and early intervention is necessary to provide these families with services to improve health outcomes for both parents and their children. I am willing to complete the relevant training needed if I were the successful applicant. The graduate certificate in child and family health nursing is something I have been interested in for a few years and I would really look forward to studying if I were the successful applicant.
I wouldn't begin a paragraph with something that you don't have. Maybe you could put it like this:

I understand how The Family Partnership Model assists the family health nurse to guide and support families within the community. My understanding is that the Family health nurse’s works in partnership with families to provide family centred care and build on strengths within the family, promoting parenting confidence and building on what the family does well rather than having an authoritarian approach. I also understand that some families are more vulnerable than others and early intervention is necessary to provide these families with services to improve health outcomes for both parents and their children. I am willing to complete the relevant training needed. I am currently looking into undertaking the training certificate in ‘Working in Partnership with Parents- The Parent Advisor Model. I am also considering undertaking the graduate certificate in child and family health nursing, as is something I have been interested in for a few years and I would really look forward to studying if I were the successful applicant.