I am new to world and character building and i want to create/build a ocean (maybe with some islands) for my ocean sim.
I ask you how to make one, and with wich userfriendly program you can make animated 3d characters and worlds?

If it's necessary: i work with blitz 3d.

You need a modelling tool, either a free one (blender) or a commercial one (max,maya, but they are really expensive).

But wich free one do you think is the most easy to use, cause im a beginner with modelling.

There aren't a lot of free modelling tools around which have the quality and features of blender, therefore I would sugguest to learn blender. But it is not easy, no modelling tool is easy, you will need lot of patience and training.

i want to create/build a ocean (maybe with some islands) for my ocean sim.

It's worth noting that most "oceans" in simulators and games are procedurally created: an artist didn't sit down with a modelling tool and make the ocean. It's fairly common to see code-based ocean effects (waves, turbulence, reflection and refraction, water color) done with GPU shader code. A modelling tool could definitely be used to make the islands and/or ocean floor (and any sea critters you want), but the water itself is almost always handled by the sim's code.

I think BlitzBasic doesn't have such commands.
http://www.blitzbasic.com/b3ddocs/docs.php