L.A.
First thing I'd do is check your district's core curriculum for math, reading, and language arts to see what's expected on that level. Second you need to come up with 3 rules and define them plus a picture of a person doing that
I'd sugges
1- Follow Directions- Looks like doing what the teacher says right away
2- Be Kind- Looks like using nice words and being careful of others feelings
3- Stay in seat- Looks like feet on the floor ,facing forward, hands in your own space
That way kids know exactly what you are asking of them and if they break a rule you can review what they should be doing.
I'd start off with a nice calendar/circle time each day review the date, the day before and after ( example Today is Wednesda, Yesterday was Tuesday, Tomorrow will be Thursday) and I like the daily assignments given out at this time ( who passes out papers, collects them, takes roll, etc)
Usually math works better in the AM and reading in the afternoon just after lunch when they've had a chance to bounce about a bit after recess and all.
Good luck and hang in there:)