Randomly generating infinite terrain

i would like to create a “seed” system into my game, where someone could type in a random number and it would automatically create an infinite, randomly generated world with certain percentages of towns, trees, rivers, ect.

this is pretty much like minecraft… EXCEPT i don’t want it to be blocks, i want it to look like real life terrain (just not blocks).

Im confused do you want someone to write that code for you?? Also it is possible if u were asking that.