Three challenges:

Poor Speech and Language: I can tackle this by modeling the desire speech, speak slowly and clear to child allow the child to speak back making sure that you are face to child so that he or she can see my mouth. Make correction to written or oral language be it grammar or pronunciation or appropriate language. If possible recommend a speech therapist. Make sure that the speech and language is at the child's level them slowly work up with the child until he/she is where he/ she suppose to be.

Being in a large classroom: Group work would work best.

Poor learning behavior: Set routines, be very consistence with rewards and consequences. Be very assertive and set realistic consequences for undesired behavior.