Ardour is a decent replacement for ProTools. As others have said, it can be daunting or cumbersome but if you’re looking for a complete DAW it is worth taking the time to learn.
If you want “just basics,” lmms will work for programmed sounds & you can use audacity for a more robust live recording interface.
Lmms is a good Foss replacement for FL studio.
Ardour is a decent replacement for ProTools. As others have said, it can be daunting or cumbersome but if you’re looking for a complete DAW it is worth taking the time to learn.
If you want “just basics,” lmms will work for programmed sounds & you can use audacity for a more robust live recording interface.