So , here you are, retired from your career, but still ready to go.
If you have ever considered setting up your own business, now is the time.
There are caveats. Watch the finances. Maybe do what you are interested in or are passionate about. Maybe do not start a restaurant. Consider how much time you want to put in to this and how much money you can afford to put in to the initial set up.
There is a lot to be enjoyed in retirement, so do not dash into filling all your time.
Contact Leo. Leo is the Local Enterprise Organisation and they have lots of courses, mentors/meetups and they are all over the country..They want to meet you.
Here is some useful information
Have a go.