My dream is to fly with a supersonic plane. Since the Concorde is no longer active, I don't think it is possible to do this with a regular plane. So how can I get onto board of a supersonic plane? Ideally it should be in Central Europe.
There are a few companies in South Africa and I think the USA that offer rides in old military jets to wealthy tourists. Same can be had in Russia and maybe some other former Soviet republics.
Fly a Russian MiG-29
There is a company MigFlug that offers flights in Russian MiG-29 fighter jets. They offer five locations within Europe, but with the prevention of supersonic flights in Europe, you may have to go for their central Russia location.
They actually only advertise near-supersonic speeds, but maybe a few rubels more get you over the threshold. Those MiGs are certainly very capable of supersonic flights.
They don't mention any prices on their web site, you have to contact them.