In the future, I will be adding more customization options.
For now, you can edit this template. I think this text that you want to change is located in in the publicShowRooms.html file found:
wp-content\plugins\book-a-room\templates\public\publicShowRooms.html
Hello,
We are having problem with the display of the steps. The texts Room List and Calendar is overlapping with the description. Is there a way to fix this? Maybe make the description shorter?

Have you tried using the “Narrow” setting in the Meeting Room Settings -> Screen Width?
Thank you yes I tried but since we have only 1 meeting room in our facility, it is a bit confusing because Step 1 (choose a branch) and Step 2 (choose a room) is unnecessary in our case. I suppose there is no way to turn these off and start directly with calendar. Am I right?
At the moment, not without editing the template itself.