Ok. Next step is to run your with initialization only. Don't send any text as yet.
Run the initialization code and you should see two rows.
If you have requested a cursor you should see the cursor on the first position (underline, box, flashing - depending on what you selected).

If you do not see this then the problem is either the initialization code or your wiring.

Edit: Albert beat me to it.

 

Thanks, Now i get text but instead of hello world, I get worldhello`vп&_F
_F b _fxello worl

Remove the loop in your code and output the text message once only.

 

Thanks, Now i get text but instead of hello world, I get worldhello`vп&_F
_F b _fxello worl

and now I changed something , and I cant get even that

 

Slow down. You are responding faster than anyone of us can type.
Take some time to look at your code and find a way of debugging your code by yourself.
Wait at least 5 minutes before firing off another request for more help.

 

Slow down. You are responding faster than anyone of us can type.

It works now

 

Now you have it working, show us and explain what you did to fix the problems.

 

Thank you all

Now you have it working, show us and explain what you did to fix the problems.

Ok, the first problem was that I didnt solder it(that was dumb, connection was bad.....)and 2. i put the text in loop instead of setup

 

Thank you all

Ok, the first problem was that I didnt solder it(that was dumb, connection was bad.....)and 2. i put the text in loop instead of setup

And sorry that I didnt tell you that i didnt solder it, i think thats the reason that recttangles werent showing

 

And sorry that I didnt tell you that i didnt solder it, i think thats the reason that recttangles werent showing

Don't say you weren't warned. From the instructions:
Next you'll need to solder the header to the LCD.You must do this, it is not OK to just try to 'press fit' the LCD!