I've downloaded Byond and launched the program, but after it loads, it doesn't show anything else on the screen. I go to the task manager to close the program and it shows its running in the background. I have a laptop running on Windows 10. I'm not exactly computer savvy so if anyone is able to give a step by step in layman's terms to prevent confusion and to prevent myself from destroying my laptop, please let me know. I remember playing Byond games back in the day and wanted to try it out again.
Sounds like the pager's loaded out of view of your screen.

Task kill BYOND, then open BYOND's CFG folder (should be in Documents -> BYOND -> cfg). Find the "pager.txt" file and open it using Notepad. Delete the "windows-pos" line entirely, it should be towards the bottom. Save the file (Ctrl+S) and close Notepad.

Once done, try relaunching.
It's not showing that line in the pager.txt file
It's actually window-pos, not windows-pos.
I don't see either of those
If you tend to use a docking station sometimes your default window when un-docked can become a host to "dead application windows" try holding the WindowsKey + SHIFT and press left, and right, to see if it will switch over to your laptop screen from invisible.