A.  I will make lego and dilicous lunch. --> I will play with lego and eat delicious lunch.

=> Corrected: The sentence is corrected grammatically. 

B. oh, my tube can I help me? -->​ Oh, my tube! Can you help me, please?

   Sorry, I can't swim. --> I'm sorry, I can't swim.​​

  Don't worry. I can swim Can I give it.   -->​ Don't worry! I can swim. I can get it. 

=> Corrected: The sentences are corrected grammatically.​​