Some buyers ship on the same or next day after receiving cleared payment.Some will wait longer.Paypal requires that sellers ship the item within 7 days in order to maintain their seller protection.
If a seller uses PayPal shipping,you receive a PayPal shipping notice as soon as the seller prints the shipping label.
If the seller doesn't use PayPal shipping,he has to manually mark the item as shipped,not all do.
Give it about a week,then contact the seller to inquire if the item has been shipped.If you can't contact the seller or he won,tell you when it was shipped,you can open an item not received dispute at around the 3 week mark.You have up to 45 days from the time you paid to open the dispute.Open no layer than day 43 to be safe.Once the dispute is open,you have up to 20 days to open a claim.If you haven't received the item or a refund,escalate before the deadline expires.
If PayPal decides in your favour,you will receive a full refund.
Once opened,close the dispute for no reason other than receipt of the item as once closed for any reason,a dispute cannot be reopened.