Baby moon???

This is our second child but our first came early so we never had any time to do anything before she came. We want to take a weekend to do something just us before this little girl comes. Just not sure what we can do that’s affordable yet something run and relaxing. We live in Michigan Incase anyone else lives in Michigan. We also plan to go to a hotel water park with our daughter before this baby comes but we want to do something just us as well. Any ideas??