Unable to access website and “wp-admin”

I’m new to this forum. Please forgive me if I mess up or break forum rules.

My website is throwing a 500 Internal Server Error.

Q1. Is this a web hosting issue, or a WordPress issue, or a website content issue (e.g., corrupt file)?

Q2. Is it possible to bypass the Internal Server Error and access “wp-admin” for my website using a backdoor (e.g., recovery mode)? This will allow me to restore my website from a recent backup.

I have accessed my website files via FTP, and I renamed the plugins folder. I was still not able to access my website (same Internal Server Error). So, I believe my plugins are not the problem.

Q3. Assuming there is a problem with my theme, what will happen if I change the name of my theme via FTP? Will another theme be activated (e.g. Twenty Twenty)? Then, will I be able to access my website? In the new theme, will I still have access to all my plugins?

Roche Terblanche

The page I need help with: [log in to see the link]