site exploded

One supposedly simple mistake last night seems to have crashed my site . . . I was trying to find info on how to put a URL re-direct on my site (from https://www.yogaforthepeople.org to https://www.yogaforthepeople.org/wp01). I found info on how to give WP its own directory (https://tinyurl.com/gdwlb) and mistakenly started following those instructions.

I went into the Options panel and tried changing the WP URL and blog URL and everything cratered from there. I tried simply undoing what I did, but to no avail. Now, both my site and my WP admin interface look like this: https://www.yogaforthepeople.org/wp01/. What the heck???

What do I need to do to UNDO what I’ve done? It’s gotta to be something simple. I didn’t do much to cause this. Ideas???