yarn start doesn't work😂

[HALLneufmilles]

Hello,
I'm a beginner.
For my project I did 'px create-react-app la-maison-jungle':

I have to use Yarn. So in the VScode Terminal I did 'yarn start':

I figured it might not be installed, so I did 'sudo npm i -g yarn':

I have never touched the terminal before, I just learned the basics to move around, copy, search, etc.. so maybe there are other updates to be made.

What do you think ?

[HALLneufmilles]

Here are my versions of nodeJS and npm at my project level:

[HALLneufmilles]

I installed it like this:
npm install --global yarn

Then doing 'yarn start' I had another problem:

I followed the link provided:

https://docs.microsoft.com/fr-fr/powershell/module/microsoft.powershell.core/about/about_execution_policies?view=powershell-7.2

I did :
Get-ExecutionPolicy -List

So I did:
Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser

AND IT WORKS!!!

For those who have the same problem...