After your settings are done, you need to choose a pattern to see how it evolves.
When you choose a pattern in the Pattern menu, the generation count will automatically go back to zero.
In the Pattern menu, you can select one of the seven prepared patterns and see how it evolves. Evolution is more interesting on a large board. These patterns are classical patterns for the Game of Life.
A pattern which does not change from one generation to the next, usually assumed to be finite and nonempty, is known as a still life.
A life configuration which exhibits a pattern which repeats in n generations is called a pn oscillator. A still life is therefore a period 1 oscillator, and a flip-flop or on-off a period 2 oscillator. The term is usually restricted to unstable finite patterns. In general cellular automaton theory the term "oscillator" usually covers spaceships as well, but this usage is not normal in Life. At the time of writing, the only periods for which no oscillator is known are 19, 23, 27, 31, 37, 38, 41, 43, 49 and 53.
A spaceship is any finite pattern that reappears (without additions or losses) after a number of generations and displaced by a non-zero amount.
Any pattern, such as the period 2 oscillator above, whose cells all die in every generation, and yet lives forever is a spaceship. Its generations both have 12 cells here.
The Exploder becomes an oscillator after a few generations.
The Pi-heptomino oscillates after 172 generations. A heptomino is any 7-cell pattern. There are 108 such objects. Those with names in common use are the B-heptomino, the Herschel and the pi-heptomino.
The Ship oscillates after 172 generations, as it is also a Pi-heptomino.
The Block ends up as a still life.
The Row is a 12-period oscillator. A diagonal row is not interesting: at each generation the 2 cells at both ends die so a diagonal row looses two cells at each generation and dies quickly. There are no birth in a diagonal row.
The Glider is a 3-period oscillator. The pattern stays the same, only it is undergoing simultaneous reflection and translation. The Glider is the smallest, most common and first discovered spaceship. This was found by Richard Guy in 1970 while Conway's group was attempting to track the evolution of the R-pentomino.
The R-Pentomino is by far the most active polyomino with less than six cells: all the others stabilize in at most 10 generations, but the R-pentomino does not do so until generation 1103, by which time it has a population of 116. This supposes of course that you have a large enough board to let it evolve without boundaries.
You can make your own initial pattern. Choose the Pattern menu and click on Your own. Then click on the cells you want to color. To cancel a selected (colored) cell, just click on it again and it'll become white.
When you are happy with your pattern, click on the Start button to start the generations or select Start in the Game menu.
Selecting Reset via the toolbar button or the Game menu will always bring you back to that initial pattern.
To make things easier, you can enable the center cell to be colored. Go in the Settings menu and select Show central cell and the central cell on the board will get colored. Having the central cell colored allows you to center your pattern for a better start!