This phrase is used here to mark where the action starts. If your language has a way for doing this, you could consider using it here.
This refers to the fifth year of Rehoboam's reign as king. AT: "in the fifth year that Rehoboam was king" or "in year five of King Rehoboam's reign" (See: rc://en/ta/man/translate/figs-explicit and rc://en/ta/man/translate/translate-ordinal)
"Shishak, king of Egypt" here is a metonym for Shishak along with the Egyptian army. AT: "Shishak, king of Egypt, and his army with him, came up against Jerusalem" (See: rc://en/ta/man/translate/figs-metonymy)
This is the name of a man. (See: rc://en/ta/man/translate/translate-names)
This is an idiom that means marched against or attacked. AT: "came to attack" (See: rc://en/ta/man/translate/figs-idiom)
"1,200 chariots and 60,000 horsemen" (See: rc://en/ta/man/translate/translate-numbers)
This exaggeration means that there were more soldiers than a person could easily count. AT: "Many soldiers" (See: rc://en/ta/man/translate/figs-hyperbole)
These are people from Libya, Sukki, and Ethiopia. The location of Sukki is uncertain, but it may be a region in Libya. (See: rc://en/ta/man/translate/translate-names and rc://en/ta/man/translate/translate-unknown)