Is it a USB connection to the computer, or do you want to insert it into a toaster? One of these is probably right, the other is probably wrong - I'll leave you to guess
Whenever you insert anything into a computer or peripheral slot/socket and you are not sure which way it goes in always have a look inside the slot to see on which side the metal contacts are and match the contacts of whatever you want to insert at the same side. Things like memory cards can easily be damaged if they are forced in the wrong way.