Get himself dressed, zip is good, laces are often difficult as they don't have a lot of fine motor skills but I would think most still have velcro shoes at this age.
Is he comfortable without you, your DH or any close family? Would he ask for help if he needs anything? He will be one of 30 and can't wait until someone discovers a problem.
If you opt for packed lunch, make sure he can opten pots and bottles.
Fine motor skills is the one thing I regret not working on. Playing with playdough, cutting out shapes (a friend did lots of cutting with Christmas cards before they ended in the recycling box), drawing dot-to-dot or colouring books.
Can he sit still for 10 minutes and listen to a story? Can he take turns playing a game?
Writing his name is a good start, recognising it is vital. He most likely will have a peg with his name and it will be all over the classroom. Think about it, 30 identical book bags, lots of jumpers the same colour, identical shoes, PE kit etc.
Knowing the alphabet and numbers is a good start. I wouldn't worry about teaching him anything in advance unless he really shows an interest.