But after four years of high school Spanish, my communication is probably even worse.

Plus I can take that four years studying Spanish and instead work on improving the translation. :-)

But if I ever leave my shoes in the library, I am ready! "Mi zapatos son en la biblioteca"

Almost ready. You're looking for "Mis zapatos están en la bibliotéca." Or maybe Mi zapatos is fine, the z might negate the s in mis.

Dude, it was just four years of Spanish... I can't be expected to speak as well as a toddler!

No, you want "mis zapatos".