How long would it take a person to 'walk' to the edge of the observable universe?

The observable universe refers to a region around the around with a diameter of roughly 92 billion light years. The reason for a limited diameter is because light, along with other signals, have yet to reach Earth since the Big Bang, so nobody knows just how big the universe is, although it is suggested that it is larger by more than a factor of 250 times the size of the observable universe. It is generally thought that there are more than 2 trillion galaxies in the observable universe.

A depiction of the observable universe, with the Virgo Supercluster (where the Milky Way galaxy is located) highlighted

Any astronomical body, be it a galaxy or a planet, is at the centre of the observable universe, relative to the said body. So the Earth is at the centre of the observable universe, but only at the centre of the universe relative to Earth. 

Therefore, the amount of time it takes to 'walk' in space (let's assume there was some kind of a hypothetical surface on which you could) can be easily calculated using the equation : 

Where S is speed in km/s, d is distance in kilometres and t is time in seconds. 

The average walking speed of a human being is about 5 kilometres an hour, which is approximately 0.001 km/s. The distance from Earth to the edge of the observable universe is about 46 billion light years, which is 4.35 * 10^23 km. The value for time turns out to be about 4.35*10^26 seconds or 1.38 * 10^19 years, by which time star formation would have ceased, the Sun would have cooled 5 degrees above absolute zero, planets would have been ejected out of their star systems and stars out of galaxies. It is estimated that only about 100 stars would be remaining at this point.