Welcome on Steemit! As this is your first post, I suggest you to use the #introduceyourself tag, as it's the one used for the introduction post.

Should i write bi lingual? What do you think?

Well, I think a bilingual post can be a great idea, so even who doesn't speak German, like me, can understand. Or you can simply write in English, it's up to you.
For now, all can I say is "Welcome aboard, I hope you'll like this platform!".