The VideoLAN Forums

How do I get on-screen data while a video is playing ?
Frame Rate, resolution , buffering etc.
Like I can while watching youtube on my LG TV.

On the top toolbar click Tools ---> Codec Information (or hit Ctrl +J)

Here's a list of vlc hotkeys which might be useful to you as well: https://www.vlchelp.com/vlc-media-player-shortcuts/