The first time I configured the categories, I renamed the default category. Now, I need to change the default category because it is the first category to be shown when I go to the categories menu. So I added a new root category but I didn't see any options to set it as default.
You can make yoru root category as default category by following below steps :
- Logged in to your magento2 admin panel
- Click on Stores -> All stores -> it will display grid for all stores
- Now click on Your main website store listed under the store column
- You will see Root Category option over there -> Select category which you want to make it as a root
Click on save and checked it, it will work
Refer below screenshot for more details :