Unable to create groups of things

Hello everyone. I am new to this board, and ST in general. I just got my hub (2.0) and a bunch of devices working. I am unable to create groups for my devices? I have searched the forums and seen that people can do it but I nothing happens if I long press on the “things”. I am hoping to creates large network of things with 30+ switches, 4 locks, 4 garage door openers, motion sensors etc… But if I cannot group this won’t work for me.

Thanks in advance.

In SmartThings universe, groups are called ‘rooms’. Here is the support article that covers the rooms.

Thank you. I understand now.