1- You have the "Type on a path" tool selected
Right-click on that tool to see the Type tool
2- reset preferences, quit InDesign
(Windows) Start InDesign, and then press (immediately) Shift+Ctrl+Alt.
(Mac OS) Hold down the keys Shift+Option+Command+Control, and start InDesign.
Click Yes when asked if you want to delete preference files.
I hope that works
Thank you. This has sorted it. So easy when you know!