are not classes provided by Bootstrap:
Introduction · Bootstrap v5.0
Based on the warnings, you haven't defined them in your own stylesheet either. Therefore, they have no effect.
The site will "work"; it just won't look like you want it to, because you haven't specified what you want it to look like. The sidebar will appear above the content, because there's nothing to tell it otherwise.
Either use the classes which Bootstrap provides
], or define your own CSS classes.