Even the 'Help' menu in Lightroom (-Desktop v6.0) has links to tutorials-
The word "collections" is used in Lightroom-CLASSIC.
In Lightroom (-Desktop v6.0) the word for creating lists of selected photos is "ALBUMS".
Regards. My System: Lr-Classic 12.3 Photoshop 24.5, ACR 15.3.1, Lightroom 6.3.1, Lr-iOS 8.0.8, Bridge 13.0.3, Windows-11.