I searched around and found this tutorial[0] on the official wiki. Seems like a decent intro to the history & syntax of the language. There’s also another tutorial[1] on the more modern iteration of the language, as well as some video tutorials[2] on using the IDE for GUI development.
[0]: https://wiki.freepascal.org/Basic_Pascal_Tutorial/Introducti...
[1]: https://castle-engine.io/modern_pascal
[2]: https://wiki.freepascal.org/Lazarus_videos