I canT recieve and send a messaage because my phone says that ' memory full, delete some data first" and i didn"t know how to delete that said data.

Actually this happens when your phone memory is full or memory card memory has no space for new messages or files,so delete some files or songs or videos in mobile phone,if the phone memory is full delete some messages in your mobile inbox,it can be message or song or audio.If you don't want to delete the messages,convert inbox messages to memory card instead being in phone memory so that you can store or send lot of messages.
delete sent items as well after sending messages

You need to delete some of your texts also go to your setting and click auto delete on it will delete the last one everytime you fill up your box so you will never run out of space.