Honestly, it really depends on how much you feel like you need to show, you know? You can always ask in the description if people wanna read chapters in the same length or if they wanna shorter ones in the future. I have this rule of "ending on a conclusion, a progression, or a cliffhanger" that I use when writing outlines for chapters, and I'm gonna get into it if you need help deciding where to split it up. Even if it doesn't help for this first chapter, maybe it'll help you with future chapters.
So, like... maybe you just wanna keep chapter 1 as a self-contained story to get people interested. Works great especially if you wanna try out a one-shot method before getting super serious with your story. That'd be a conclusion within my rule. Leaves people going, "that ended well, I wanna see what happens after."
Or.. maybe, you wanna have something continue on in a logical way. Say a guy has a goal of going somewhere, the ending is him walking there. A calm ending, but an effective way to progress to the next chapter. Or in the case of a fight, a progression would mean increasing the stakes of the fight using some new power-up. Leaves people going, "This is getting interesting I wanna see how this continues"
Maybe you just feel a little gutsy. A cliffhanger's good now and again, but you gotta use these more sparingly than the other two. Save this for the best moments. You gotta have something extremely good in the next chapter in order to make up for.. not telling them what happens next xD Tends to make people either go "wow what a cheap way to end it" or "I need to see what happens next!!" but that's based on your delivery of said cliffhanger so keep that in mind.
So yeah, that's all I got for now, good luck~