Welcome to the forum.
It looks as though the plane you started on was the wrong one. If you go back
to your initial sketch just RC on the sketch in the feature manager and select
"edit plane" then pick the plane that is 90° from the one you currently have.
Also if you post an image I can see for sure that this is the case.
You can change your scene too, so the floor references a different plane. See the attached picture. use the drop down and chose selected plane, the select the bottom face of the part.
Capture.JPG 69.0 KB
Thanks. That worked great.