Look in the Help menu or User Guide PDF for "Work Environment". If the toolbar is a custom toolbar, then you must save your menu scheme after setting it up. If you are just talking about position and visibility, then you must save your Palette Scheme with a name.
Ideally, you should set up a full custom Work Environment for yourself (top of the Work Environment tree on the left of that dialog) and save that.
Finally, whether you only do a few schemes, or a full Work Environment, you must Export the schemes (or if you export the Work Environment, all used schemes are exported) to that they reside somewhere on your disk and can be re-imported if you have to reinstall ArchiCAD, or change machines.
Cheers,
Karl
One of the forum moderators
AC 28 USA and earlier • macOS Sonoma 14.7.1, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB