that's kind of writing is grammaticly wrong. but don't worry lesten to the radio and watch film alot, try the book "grammer in use" it's can answer all of your question about grammer.
that's the right sentences:
1-you didn't need shout at him,______________?
2-he must went to bed,_____________?
your answer is:
1-you didn't need shout at him, did you?
2-he must went to bed, didn't he?