what do you do once you win a land auction

[Lindal Kidd]

When you win, you will be automatically billed for the purchase price and your tier level will be increased, if necessary.  All you'll need to do is go to your land and start building!

[Lindal Kidd]

When you win, you will be automatically billed for the purchase price and your tier level will be increased, if necessary.  All you'll need to do is go to your land and start building!

[KingFuture]

Ty so much

[ChantillyTex]

From the Auction FAQ it looks like you don't have to do very much, although they do suggest visitng th auction site to check on the status of your bid to see whether or not you won.  If you did win, the land should be assigned to you within 24 hours provided that there are not any billing problems.

How will I know if I win?

We will notify you by email if you win; although you are responsible for determining if you have won by visiting this site and checking the status of your bid on the My Bidding Activity page.

Collecting Your New Land:
How will I know when I can take possession of the land?
Unless there is a problem with billing, winners of auctions will be assigned the land within 24 hours.
How soon do I have to buy the land I won in the auction?
The land will be assigned to you as soon as the auction closes and billing has run. This may include an increase in land tier.
How do I take possession?
The parcel has already been assigned to you inworld once the auction ends and the billing has run.
Is it possible to avoid tiering up by releasing other land before confirming a new higher tier?
Arrangements with tier should be made prior to participating in an auction. Land won in auction will be delivered to the winning account and will affect peak land use.