What Is the Limit Difference Between Getting Money from a Cosigned Loan and Getting Money from a Loan?

loan

My dad works on wallstreet, it fourty something, and has been told he can take up loans of up to 5 million dollars for a affair loan.
I am out of college, was a manager at a small affair, and want to buy an existing small businesses.
I have no capital. There is no way I can get any funding.
My Dad says he will cosign a loan. Does this mean I can take out 300k at a reasonable rate from the bank?