Hi Anniepannie
Welcome to the forum.
You might want to have a look at the following FAQ which explains where everything is;
www.benefitsandwork.co.uk/guides-for-claimants/faq/forum The answer to your question is absolutely ....... nothing.
PIP carries on as it is, after you reach state pension age. If you are in receipt of the standard rate mobility then you will not be able to claim the enhanced mobility you would stay at standard even if your mobility has worsen, if you are not in receipt of the mobility component then you would not be able to claim the mobility component after SP age.
The daily living component can change after SP age.
Gary