Welcome everpom,
iirc, there were versions, where the dock widgets are disabled by default, seems this is one.
Go to the
Widgets menu, open
Dock Widgets and activate the
Layer List or
Block List or anything else.
Then you should get the widgets on the right side, where you can manage layers or blocks.
Armin
investing less than half an hour into Search function can save hours or days of waiting for a solution