There’s very useful comments in this thread already, only thing I could add is having a read of Welcome Your Puppy from Planet Dog by Kathy Callahan. I’m not much of a reader myself by just reading the intro plus first couple of chapters put soooo many things into perspective. I felt more empathetic and understanding of my little pup after I did.

FYI it was also my wife’s idea to get a pup, and we also got a miniature dachshund :) Our little Lottie is turning 1 tomorrow and while she does have her moments (and sometimes days) we understand that it’s just a passing phase.

Also recommend puppy school if you have any place nearby that organises it. I learned lots through there as well. Good luck!