In different trailers of LBP 3 I saw playing tennis and driving tanks,etc would be possible but I finished the story but did not play that so far. Do I have to search them or are they only available with dlc and if yes in which dlc contains tennis and tank driving levels?

I think those were creations by the developers to get us excited for the game. They aren't in the story, but it's possible to create them in levels.

Oh I have no idea how to do rules for tennis in this game.

Rules? How you mean, while I do tennis as hobby, I don't get what you mean.

I mean that I don't know how to set the rules and the all the other objects to make it work in lbp.

You mean logic? Those levels were pretty advanced and it would probably take a lot of skill to make them. I'm sure that they're community levels, though, so if you do a little looking in the community levels, you might find them. If you're looking to make a level, watch the tutorials on LBP.me and get acquainted with the logic and you'll be making levels in no time.