Shall step forth means rule, govern
Dr. Zvi Betzer says:
In Ugaritic the verb darakh appears in the sense of 'to rule, govern'.
Ayelet-Hashachar Hareuveni says :
the star is a shield in the shape of a star and the soldier stepped upon the part of the shield that was between two triangles and thus the shield had been stuck into the ground
Balaam is Laban the Aramean
Rabbi Shlomo Riskin says:
…the classic Targum (Aramaic interpretation) of Yonatan ben Uziel, identifies Balaam with none other than Laban the Aramean, uncle of Jacob-Israel
I see him but not now ((Num. 24:17), this refers to David; I behold him but not nigh (ibid.) this refers to King Messiah; A star shall step forth out of Jacob (ibid.) this refers to King David; A star shall step forth out of Jacob (ibid.), this refers to David; and a scepter shall rise out of Israel (ibid.) this refers to King Messiah…
The first time in the Bible that reveals any connection between the word "star", the word "David" and the words "nation of Israel" is in Bilam's speech. When Bilam sees the nation of Israel he says:
"There shall come a Star out of Jacob, and a Sceptre shall rise out of Israel" (Numbers 24:17). Rashi and Iben Ezra comment that Bilam's prediction is about King David. This is only a speculative connection that does not point on the shape of the Magen David (Star of David). The star in the verse refer to Bar Kochba
James Trimm says:
Bar Kosiba was renamed Bar Kochba (son of the star) and was declared the Messiah based on Num. 24:17.
The star in the verse refer to Jesus
Early Christians did believe Jesus was born under the Star because the prophecy of Balaam (Num. 24:17) said that the Messiah would be revealed by a regal Star.