Hi John.

1. Replace that image >images/2024/05/15/login-registration.webp (keep the same name and file type)
2. In Joomla Login not all can be removed, but check Menu item "Login" settings
3. For whole rest use Custom CSS. Before you will ask me more in CSS topic, read >> https://www.joomshaper.com/blog/which-line-of-css-i-have-to-edit-code-inspector-in-action

For example, you can hide all links "Forgot...." with simple...

.login  .list-group .list-group-item {
  display: none; visibility: hidden; cursor: none; }

And Passkey button is Joomla native plugin.