Thanks for your help…Its not homework as im the teacher ;), i put in libraries because as far as i know pgui is a library as p5.play. So the problem was not related to p5 but to p5gui.
It doesnt work because it doesnt load the globals, it doenst appear any gui or anything like the code in global mode.
About index.html it could be, but i read it many times, and i put the p5.gui and quicksettings.js just under the p5.js library
The question is vague because i dont know the problem, i have other sketches in instance mode (no using p5gui) and they all work fine
The desired result is something like:
By the way in the index, why did you put scripts inside body, shouldnt be better to put in the head, so you dont start game till its loaded … ??
ps: as a good student i took in consideration your recommendations, and updated the title and tags of the question 