How can we keep Hashem's command to observe the Feasts when we cannot sacrifice in His Temple as it lays in ruins?

do you have to obey the ten comments

When was Rosh Hashanah first celebrated? I understand that it represents the the sixth day of creation. Is that an accurate rendering? Thank you

why do the women shave their heads and wear wigs?

Dear Rabbi Due to a family emergency I was unable to attend prayers for the second day of Rosh Hashanah. As well as I can remember this has never happened to me before. Is there some way to make up for this omission? Is it possible to still say the prayers for the second day during the ten days? Any advise would be most helpful. Thank you