Error when using cd- saying file is nonexistent

How do I stop this error from coming up.

Please help ;(

[Stephen23]

cd ~/Desktop/Flanker/sub-01
%  ^^ you forgot this (read DGM's answer)

Answer 1

[DGM]

You're trying to cd relative to the current directory, instead of relative to ~/

[DGM]

I suppose I did.