Can I change any text of the widget to my own?

Yes, you can easily change any text of the widget in its settings on the Text tab. There you can choose one of 10 languages of the widget.

Here you can translate your descriptions and names of resources, tariffs, fields, tips, etc. To do this, add a new translation key, for example Hall. Enter a translation for it, for example Room.

Then in the settings use this translation key in braces, i.e. {Hall}.