Birchat Hamazon

If one forgets Ya’aleh Veyavo but remembers before saying Hashem’s name at the end of Bonei Yerushalayim, he goes back. If one remembered after that, but before beginning the next Brachah, he recites the extra Brachah printed in some Birkonim. Some, including Chabad, hold that If one already began even the first word of the next Brachah, one must begin Birchat Hamazon again at night, but not during the daytime. Best to check with your Rabbi.

Both the Harachamon of Chag and Rosh Hashanah are recited, in that order. One does not add a Hey when saying Oseh Shalom in Birchat Hamazon. Some have the custom after the meal not to sleep right away but to learn something small.