#These latter five kings joined together

The information that their armies were with them can be made explicit: AT: "These latter five kings and their armies joined together." (See: [[:en:ta:vol1:translate:figs_explicit]])

#Twelve years they had served

The events in verses 4-7 happened before verse 3. Your language may have a way of showing this.

#they had served Chedorlaomer

They probably had to pay him taxes and serve in his army. AT: "they had been under the control of Chedorlaomer." (See: [[:en:ta:vol1:translate:translate_names]])

#they rebelled

"they refused to serve him" or "they stopped serving him"

#came and attacked

They did this because the other kings rebelled.

#the Rephaim ... the Zuzim ... the Emim ... the Horites

These are the names of people groups. (See: [[:en:ta:vol1:translate:translate_names]])

#Ashteroth Karnaim ... Ham ... Shaveh Kiriathaim ... Seir ... El Paran

These are the names of places. (See: [[:en:ta:vol1:translate:translate_names]])

#El Paran, which is near the desert

This phrase helps readers understand where El Paran was.  It can be translated as a separate sentence if necessary. AT: "El Paran. El Paran is near the desert." (See: [[:en:ta:vol2:translate:figs_distinguish]])