how in the heck am I supposed to retrieve my first purchase ever from this paper wallet if the passcode I believe I used, is not working?

Sadly, if you created a BIP38 paper wallet and lost the password, then your bitcoins are locked away forever. A password protected wallet would be kinda useless if there was a way to circumvent the password protection. With financial sovereignty comes responsibility, hopefully you only have a small amount locked away in that wallet.

If it was just a matter of one wrong keystroke, you can maybe look up some sort of password brute-forcing software online. This might end up being a fair bit of work, but it may be possible to recover your funds this way.

Best of luck.