In timetable mode I only see the services between Hicksville and New York Penn. The services between Atlantic Terminal and Hempstead, that were there in TSW2020, seem to be missing when selecting the M7.
You have to change the livery of the train. You then get the option of 6, 8 and 10 car sets. When you select the train before selecting the weather, you should see the option to change the livery.