Okay I installed a demos folder I went into a game by loading the game from SPLORE, and then exiting back to SPLORE.
Then, exiting SPLORE. Then I got into the editor. Am I missing steps because I still try to export the game to html and js but the problem is that I can't find it on my computer still.

I just need a step-by-step instructions somehow or I'm missing something.

exit from splore and exit from editor to get to the command prompt

Well I tried that but it still didn't work.

Also when it says exported meas.html and meas.js I can't find the files on my computer.

don’t just say «didn’t work», show what you did or types and what you get (with copy-paste or a screenshot), otherwise people don’t have any information to help!

after you export to html, type folder to open your operating system file explorer. the official docs explain many things really well: https://www.lexaloffle.com/dl/docs/pico-8_manual.html#_File_System