'package' is probably referring to drugs aka packs - 'my whip game proper' = i have nice cars
A "package" is urban slang for a delivery of drugs. His "whip game proper" means that he knows to use inconspicuous cars at legal speeds to not alert the attention of authorities when delivering said drugs via automobile.
basically wayne is saying he is all about his money(cake,bread,etc.) and betty crocker is a name brand of cake mix