There are published pages on the website that are not mine

You should first check if your website has been hacked. Tools like Wordfence help to check this:
https://www.ads-software.com/plugins/wordfence/

Furthermore, you should check whether the call of these URLs also lead to a target. If yes, then your website might be hacked. Possibly also your hosting, if the files were stored there parallel to WordPress.

Here is an article that roughly describes how to proceed in case of a hack: https://www.ads-software.com/support/article/faq-my-site-was-hacked/