ok Sirine Benyounes,
we told you 2 times already that
you NOT have to try to execute p5.js … like a app
as it is called from HTML ? like a library? sorry that poor wording.
hm, could do, but that is not the point here.
you do what i show in the pictures, call
index.html
- by browser
- by double click
and you make a sketch.js file by any editor with your code.
again if you not get the basics running you please work in the online editor
to learn the coding … of p5.js “language”
your way is not good for a beginner start
as it misses the working environment what is provided
by the online editor or by the processing 3.5.3 p5.js mode…