This is your answer. You are under 21 and you are a live in Wisconsin. It means you cannot have an out of state license and you have to be 21.
Legal definition of a minor is someone that has NOT attained their 18th birthday. (For HHK)
ID also "May issue" a concealed license to someone under 21, but over 18. It is shall issue at over 21.
As in WA, I believe WI limits your out-of-state license to 21 and over, even if you are licensed in another state, and I also belive WA and WI are the same in that if you reside in WI, you have to carry on a WI permit within the state of WI.
Also, as in WA, I believe Open Carry is legal without a license to residents 18 and over, in certain cases...
there you will have to read the law for exceptions.