How to create a form in my Plugin?

I am developing a Plugin.

I’ve developed the core of my plugin, I’ve also developed a Widget that I need to use with my plugin, but now I don’t know where else to find information.

What I need to do, is this: in my Plugin’s Widget I want to put a link “Register here!!!”, and when the user clicks there take him to a page like https://mysite.com/my_plugin_register

And there display a form so the user can register.

Is there any action hook to do this? Where can I find any example?