Question:
Why didn’t God just tell Abraham where He wanted Abraham to go in Genesis 12:1?

Answer:
The Lord wanted Abraham to act in faith and to walk in faith, seeking His will daily.  If the Lord had told Abraham exactly where to go, it would have been possible for Abraham to reach his destination without crying out daily to the Lord.

Psalm 86:2,3 – “Preserve my soul; for I am holy: O Thou my God, save Thy servant that trusteth in Thee.  Be merciful unto me, O Lord: for I cry unto Thee daily.”