Gimp 2.10 users
Gimp 2.10 as first installed looks totally different from Gimp 2.8 but don't panic, the difference you see is largely cosmetic.
Gimp 2.10 when first opened :-
It looks nothing like Gimp 2.8 that I have used in my videos :-
However with a few simple tweaks it can look like this:=
To change the settings in the top menu select EDIT > PREFERENCES > THEME and select the SYSTEM line, then select EDIT > PREFERENCES > ICON THEME and select the LEGACY line.
Select OK at the bottom of the PREFERENCES window to save these settings and your Gimp should look more like my videos!