Some Resources to proceed with your learning:
This is a copy of a book introducing P5JS covering all basic features.
I suggest that you have a look, copy and paste some code snippets into the editor to execute them and then try to understand what is happening. The text will help you further with that.
In the coming two lessons we will focus on the content in Chapter 7 (images) and 8 (sound). To try out the projects, you need to download the images and sound files provided. They are in media (images, sounds, etc.), you can download them from this Github Repository.
If you are not too comfortable yet with p5js, I encourage you to start with the earlier chapters first and try to get deeper into programming.
Here is a video describing an implementation of the Flappy Bird game with P5JS.
This is a link to another Github repository with the source code for the game. You need to open the files, copy and paste the content into files with the same name that you created in your p5 editor. To create the files pipe.js and bird.js, select “Sketch” in the editor’s menu and then “New File”. Enter the file name with extention. For sketch.js and index.html just replace the content of the existing files.