xournal is not available for Mac but there are plenty of alternatives that runs on macOS with similar functionality. The best Mac alternative is Microsoft OneNote, which is free. If that doesn't suit you, our users have ranked more than 25 alternatives to xournal and 16 are available for Mac so hopefully you can find a suitable replacement. Other interesting Mac alternatives to xournal are Foxit Reader (Free Personal), Xournal++ (Free, Open Source), GoodNotes (Paid) and Stylus Labs Write (Free).
GloboNote is a free and easy to use desktop note taking application. It helps you to create to-do lists, reminders and other notes in one place. There is no limit in the number of sticky notes you can create.