If you made a "Best Offer" and it was accepted by the seller you should
get a notification from the seller. If the seller did not accept your offer, then
go back to your sellers listings, and look to see if it has been re-listed. You
could also "contact seller" and ask about your offer.
When you have won an aution, you will be sent an e-mail from e-Bay to
advise you that you won the auction. You will also see one if you do not
win, saying "sorry you didn't win" and if you have been outbid during
an auction you will see one urging you to bid again. So, if you did not
receive a "winner's e-mail". Then I'm sorry,you didn't win it this time.