Can't use login page

When I try to access my login page

https://godwords.org/wp-admin

I instead end up on my home page with no WP admin bar. To log in, I have to go to

https://godwords.org/wp-login.php?registration=disabled

This is a kind of error page. I’m quite sure this might be due to a security plugin I’m no longer using…I’ve added, tested, and removed tons of different plugins over the years.

Question:

1. Does anyone recognize the situation above? If so, what file(s) might be involved in this process? I’d like to be able to log in normally.

2. Is there a way to “reset” my WP installation so that changes plugins make can be undone effectively?

Thanks ahead of time for your help!