HI and Welcome to the forum, you might want to have a look at the following FAQ which explain where everything is
Welcome to Benefits and Work ESA is an income replacement benefit. As such, it will no longer be paid once you are of age to claim the State Retirement Pension. You should contact DWP to apply for this to be paid.
Claimants already on PIP will remain on the same rate after retirement, pending periodic reassessments. Claimants still on DLA who were under the age of 65 in April 2013 will be switched to PIP at some stage, even if they are of State Pension Age by that time.