Where can I find centers to learn german?
You can go to @Berlitz Language Center , they have German courses there.
Where can I play pictionary preferably with argeeleh?
@Bargo's they have argeeleh and pictionary too!
Where can I find a place to relax and rest for a week?
If you want something right in the middle of dubai, @Park Hyatt Dubai is an amazing option!
Where can I buy steel bars with different weights ?
I think they sell everything u need @Carrefour كارفور
Where can I find visking tubing (dyalisis tubing)?
I'm not sure of an exact store but I know your best luck is downtown (AlBalad). Good luck!