Changes in new UI - docking windows and in context menu

[suzuki]

Hi, I've missed a few versions, but despite a little reading, I'm still running into two small issues, 2.1.7 (Win10), probably due to ignorance on my part:

1) I can't seem to (re-)dock windows anymore. I had some windows docked, but on closing and reopening them, they just float. And I can't seem to resize or move the main Geometry window at all. I did read about holding the shift key down, but it doesn't seem to do anything. What am I doing wrong???

2) Is the "Select" context menu gone (maybe a few versions ago)? Or maybe moved? Or am I just failing to access it?

Appreciate any help!