I was taught that if a story continues in the next issue, end with a climactic cliffhanger.
And, as I learned on my own, that “rule,” taught to me by Mort Weisinger, like pretty much all rules applied to creative work, is far from absolute. There are plenty of ways to go about continued stories. More on that later.
But first, the end-with-a-climax/cliffhanger way:
In the first issue, introduce the characters and establish their situation. Introduce the problem, threat, opportunity, whatever that generates the conflict. Develop the conflict to an intense climax/cliffhanger, and end there.
Second issue, elegantly, succinctly introduce the characters. Re-establish the climax/cliffhanger situation from the end of last issue. If possible, intensify the situation. Resolve the climax/cliffhanger—that is, brilliantly get Batman out of the death trap or whatever. Do it in such a way that A) the overall conflict is not resolved but is in fact increased, or B) a related-but-new, greater conflict arises to succeed the resolved conflict. Develop that new or increased conflict to an intense climax and bring the story to a resolution.