1)
Having already instructed Moshe (in Pasuk 3) about bringing the bull and the rams, why did Hashem repeat it here?
1.
Ramban #1 (citing the Ibn Ezra): Hashem is telling Moshe here that, when he brings them to the Ohel Mo'ed, Aharon and his sons should lean their hands on them.
2.
Ramban #2: In the earlier Pasuk, Hashem did not tell Moshe exactly where to bring them, and it would have sufficed to bring them to a point before the entrance of the Ohel Mo'ed, where Aharon and his sons were waiting. Now however, He instructed him to bring them to the entrance of the Ohel Mo'ed, where they would perform Semichah, followed by the Shechitah (in the following Pasuk).
