Depends where from, where to and how heavy it is.
it depends on the stamp then you will know how many stamps you will need
how many first class stamps does it take to mail a 4 oz letter and package
this would depend on the weight of the package
80
23-30 stamps depending on the weight of the package.
It depends on where from, the weight of the package and what transport is used.
You need 1 stamp to mail a letter/package throughout Canada
That will depend on the weight of the package and the postal class (e.g. parcel post, media mail, priority) of the package.
You would really have to know the weight and dimensions
The answer depends on the size of the cards. It could be just one large package.
"Regular size package" is a very nearly meaningless term. If you really want to know, go to your post office. They can measure and weigh the package and give you a definitive answer as to what the postage will be.
That will depend on the value of the stamps you have. If you have one cent stamps you will need 190 of them. If you have ten cent stamps you only need 19.