First official Acts

[Lev. 9:1] And it came to pass on the eighth day, that Moses called Aaron and his sons, and the elders of Israel;
Number 8 means new beginnings; a resurrection life. The ministry of being a priest is on the basis of resurrection power of the living L-rd within us. So not leaving for 7 days he was saying, look, don’t try to operate as a priest on any basis other then resurrection power. It will never work. You will produce only death if you try to do it any other way!
The first of their official acts was to sacrifice of another sin offering to atone for the defects of the inauguration services; but that sacrifice did not consist of a bullock - but a calf (Reference to Aaron’s sin in the golden calf?)
The pronouncing of a benediction on the people assembled in the court was a necessary part of the high priest’s duty.
Come down from the offering for the altar was elevated above the level of the floor, and the ascent was by a gentle slope.
Moses, according to the divine instructions he had received, accompanied Aaron and his sons to initiate them into their sacred duties. Their previous occupations had detained them at the altar, and they now entered in company into the sacred edifice to bear the blood of the offerings within the sanctuary.
The glory of the L-rd appeared unto all the people was perhaps in a resplendent glow above the Tabernacle as a fresh token of the divine acceptance of that newly established seat of His worship.
What a dramatic scene, when everything is completed exactly as G-d had commanded. A supernatural fire proceeds which consumed in a flash all the rest of the offering upon the altar, was a sign, not only of the acceptance of the offerings and of the establishment of Aaron’s authority, but of G-d’s actual residence in that chosen dwelling-place. The shout was a shout of victory, an expression of their sense of awe and wonder at the fact that the G-d of glory is in their midst!