@0takuguy this is the release order:
1. Escape from Nagazora
2. St. Frya High
(Note: Since the whole HI3 manga started more as a GGZ backstory thing, these two arcs above might not make the most sense in the in-game HI3 story. You will just have to accept it for how it is. A easy spot to differentiate between "GGZ-aimed" chapters and "HI3-aimed" chapters is that Kiana had looser braids in GGZ, almost as loose as Bronya's drills)
3. Azure waters/Violet sea
4. AE invasions
5. Sakura samsara/Gratitude arc
6. Moon Shadow
7. Purple kite
8. Second Honkai Eruption/Second Lawman arc (CN on going)
There are also some side stories that were released in between the other arcs. These can be read at any point in any order:
1. Secret of the God Keys (CN on going)
2. Mystery of Stigmata (cannon but not considered to be in the same universe as some plot lines don't match with the game)
3. Gemini Origins
4. Gemini Invasions (CN on going)
And there are spin-offs that are slice-of-life stuff about the valks, can be read in any order:
1. When Kiana plays Honkai Impact
2. Valkyries' Dining Escapades (CN ongoing, source material for the cooking anime)
3. Summer memories