I've set a few pages to require login via the Access rules.
If a user tries to access one of these pages without being logged in, they are currently shown the 404 page.
How can we set custom login page?
That then redirects user to the page they were trying to access, after logging in?
/log-in/?redirect_to=/member-only-page/
You can't set redirects with Access, but you can set Custom Contents Templates or Layouts as the "error" message instead of a 404.
This is described here:
https://toolset.com/documentation/user-guides/setting-access-control/#choosing-what-to-display-when-read-access-is-denied
If you need redirects you need Custom Code (It cannot be done with Toolset Access)
However if you want a redirect AFTER you login, you can just use the Toolset Login Management ShortCodes.
Something similar is elaborated in depth here:
https://toolset.com/documentation/user-guides/building-the-my-account-page/
This is the ShortCode you'd be using https://toolset.com/documentation/user-guides/views-shortcodes/#wpv-login-form
Please let me know if you need more information about this.