Can't log in any longer

I am working for a small charity and yesterday an error occurred while I was working on the blog site – I may have messed something up – and now we cannot log in to the account and our website is now an error message. Currently, our charity has no site which means we cannot collect donations or otherwise legitimize the charity. I really need help to find out what has happened. I used to log in via https://pearlchildren.ca/wp-login.php but now this just loads the error message as seen on the website. The URL for the site in question is https://www.pearlchildren.ca. Thank you so much for your help.

Jesse