Consider chaning to zsh as recommended in the output. If you do this you can press the TAB key to complete names of files to avoid tpos.
It looks like you are trying to change into a folder called "L1 demo". If so, that folder has a space in it. You need to enclose the folder name in quotes like this:
cd "L1 demo"
Or escape the space character with backslash
cd L1\ demo
So that the shell understands it to be a single argument to the cd command.