Can i change the biome by replacing the sand with dirst in minecraft? I basically want it to be able to rain there, that s the point?

I think you can do that in settings -- or the when your on the screen before you click on the server/game. Not sure but when you do "custom" under "more world options", you can select a biome. But biomes in normal mc are all over the world -- just walk a lil' to find the one you need.

No, no way to change a biome without mods - this isn't terraria. However, as the misinformed guy that also commented said, they are all really easy to find and there are infinite of each of them - just find one, or you'll have to fiddle with mods.

No, you can never change a biome unless you use an edit tool.