Class One. Shabbos has two levels: 1) The delight of Shabbos which happens by itself, 2) The delight of Shabbos which is connected to Avoda. Rosh Hashana is also about delight, but it is higher than both of the aforementioned levels, it reaches the מקור כל התענוגים- the source of all delight. It actually isn’t revealed as pleasure but as fear though it is the source of all delight.
Class Two. Rosh Hashana is about renewal. Every Mitzva is a ‘Chidush’ as we create more Keilim and bring forward more Ohr. Rosh Hashana we crown Him as king and all the value in all the Mitzvos that will follow depend on this Chidush which is achieved Rosh Hashana by blowing Shofar in a way that is new, Why Shabbos we blow only in the Beis HaMiKdash but Torah, we say Shofaros everywhere. See beginning of 5743 for the next Maamar in this Hemshech.
