On holiday so can't post

[HoliHormonalTigerLillyTheSecond]

What do i do?
Something has sold on ebay and am not there to post it...?

Did you put on your account to say you were on hols?

Best thing is probably to message buyer and say you're away and can either post on return (in x days) and offer to refund

In your account settings you can set 'holiday time away'. Use that to prevent any more sales.You should apologise to the buyer, offer to cancel the sale and refund them. https://www.ebay.co.uk/help/selling/selling-tools/time-away?id=5137

Why didn’t you end the listing or set your time away up?
Ultimately you’ll need fo message the buyer and offer to either refund or post when you’re back.

You grovel an apology to the buyer and ask for their understanding for your oversight. Apologise repeatedly for any inconvenience.

Offer refund if (you cancel sale to get fees back) if they don't want to wait.
Do all that quickly & most buyers won't hold a grudge or neg you for it.