Competition winners will get to visit the Olympic site
About 300 people will visit the Olympic site and hundreds of cultural events across the UK will take place during London 2012 Open Weekend.
The programme, which begins later and lasts until Sunday, marks the three-year countdown to the Games.
London will stage 74 events including sports activities, exhibitions and a hip-hop interpretation of Shakespeare.
Olympic chairman Lord Coe opened the events by trying a few jumps and plies with the English National Ballet.
But it is the Olympics itself he is most concerned with limbering up for.
"I broke 13 world records in my career," Lord Coe said.
"I do not intend to break a 14th by being the chairman of an organisation that does not deliver on time as well as within the budgetary envelope."
Winners of various competitions and prize draws run by the Olympic organisers will get an exclusive preview of the Games site in Stratford, east London, on Sunday.
Among special guests participating at the events will be Mobo award-winning artist Akala, who will see youngsters at Southbank Centre perform a medley of scenes from the bard's plays reinterpreted through hip-hop.
London Mayor Boris Johnson said: "The London 2012 Open Weekend is about gearing us up for this incredible moment and encouraging everyone to get involved in sports and culture."
Events are also taking place across the country, including dance workshops, singing on buses in Northern Ireland and public theatre performances in Wales.