WordPress Plugin Help

Hi, I'm a busy developer and have an itch I need to scratch. I have been learning about WordPress Plugin development and currently have some questions around the JavaScript to include on a plugin configuration page (and styles), menu for plugin, reliable ways of fetching the request including all headers (just $_SERVER or is there a better WP API?) And questions around hooking into any login to customize it, eg to look at last IP and device, enforce 2FA and captcha perhaps).

I have done a lot myself but need some assistance and need to ask some questions when something isn't obvious to me, or there seem to be several ways to do something.

What I want, for now:

I have my layout, plugin class and some code, it activates fine and creates its database table on activation and drops on deactivate same for the WP options API items

Creating a plugin menu and pages, and styling them and adding/enqueing page's JS code

Creating a form for plugin configuration page and responding to user config options (simple form with a few options)

The best way to find all the current request data so I can inspect it if it's not just in $_SERVER and with currently logged in user and page info

Advice on hooking into logins (leave blank for now)

Thanks for your interest and help!