Need help to create an installer

I'm the developer of Lupo PenSuite, I have started to use NSIS to create the Extraction Wizard of my collection. Now I would like to improve it, in particular I'd like to implement an Update feature in the installer. I thought to this structure:
- Welcome page
- License page
- Choose modality page (that allow to choose if do a New install or Update an existent one)
New mode:
- Directory page
- Install page
- Finish page
Update mode:
- Directory page (that allow to select also the old directory)
- Install update page
- Finish page

Now, I have tried to do something, but I can't understand how to create and manage customized pages. Can someone help me? Thanks! 😁

Read the docs for nsDialogs (under ${NSISDIR}\DOCS).

The doc is basically a step by step tutorial on custom pages. The steps are very easy to follow and should get your started.

There are also several posts here in the forums regarding nsDialogs.

I have tried to read it, but I'd like to use the MUI2 and that info are about the old one. Can someone link me a fully functional script that has a custom page? thanks!

For MUI2 info look at:
NSIS/Docs/Modern UI 2/Readme.html 🙄

There is a "Custom pages" section in that document...