Your very first line shows the basic lack of understanding:<quoted text>
ya, right. Of course I edited for space, but that's about the jist of it.
Strange that one fish (or a species) would somehow grow legs because "life is better on land" while at the same time learn how to breathe air instead of water.
Meanwhile, other fishies thought it was better to stay in the water...
"One cell turned into fish that grew legs
but not all grew legs, some stayed as fish"
There were many, many stages between the single cell stage and the stage of fish.
As to some fish evolving into land animals and others staying in the ocean, do you really think all fish experience the same environment? Do you really think that the selection pressures on fish in swamps is the same as for fish in rivers or in the open ocean?