Just type in a map size and go from there!
Because of how the map is printed out, I recommend a map size > 75 so the screen displays properly. Fullscreen is also suggested.
Voronoi noise is a particular type of noise, which is an algorithmic series that creates semi-random values that are connected to the values around it. You can look up 'noise function' for a bit more detail. Cellular Automata is another function which assesses tiles to create smoother terrain. For my terrain, the rule is that if less than three of the four surrounding tiles are a different color, there is a 1 in 3 chance that tile will change color. @AbhayBhat