Im not sure what you mean by console/dev tools but i haven’t messed with any of that.
Most major browsers include some kind of developer tools (usually by pressing [F12]). For JS, I prefer Chrome’s dev tools, but try out whichever browser you prefer.
The first jquery script is the jquery library and the second is the actual js file like the main.css
I couldn’t say without actually seeing what those files contain,* but they are named as if they are both jQuery.
If I pull in jQuery only once, your script works as expected:
* you need to use fully qualified URLs on codepen; relative URLs like “main.css”won’t work.
Don’t worry about being “new to programming” or making “stupid” mistakes. Everyone is/was a beginner at some point; it doesn’t mean you’re dumb. Just keep putting forth the effort, and you’ll learn in due time.