Some comic book specialty stores might have it. You could also check out local comic conventions or fan events, as vendors there sometimes sell JoJo manga in English. Another option is to search on websites dedicated to selling manga.
You can try looking on popular online bookstores like Amazon. They often have a wide range of JoJo manga available in English.
Chapter 345, "Mirror Valley Defense Commander Luo Ming, Beast Tide, Great Xia's 6 Armies (Part 2)", is the clearest early answer because it turns Mirror Valley Defense's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Last June, Luo Ming led his team in Arrow Bamboo Forest to... and follows through with Now excluding the eight districts within Xia City, there are 26....
Chapter 69, "Received Two Advertisements on the First Day", is the clearest early answer because it turns Brother Yan's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Since the phones issued by the program team couldn't log into Weibo,...
Chapter 182, "Director Sun Still Knows How to Stir Things Up", is the clearest early answer because it turns Brother Shaojing's situation into a concrete plot event.
Chapter 149, "Director Zhang, I heard you've encountered some troubles lately", is the clearest early answer because it turns Zhang's situation into a concrete plot event. Early on, Seeing that Zhang Cheng's glass was nearly empty, Du Qinglian....
Chapter 338, "The Adulterer is Far on the Horizon, Yet Close Before the Eyes", is the clearest early answer because it turns Taishi Chair's situation into a concrete plot event. Early on, Tang Jinyu, dressed in a light apricot Cheongsam, sat indifferently....
Chapter 348, "Schemes and Counter-Schemes, the Five of East Ridge, Zhu Yang's Threat, The Dust Settles (Part 5)", is the clearest early answer because it turns Lu Yang's situation into a concrete plot event. It opens with Zhu Baixu, challenge ring number 1." "Lin Qiang, challenge ring... and closes on Leader, something's off, Wang Wu is heading towards ring number 1!"....
Chapter 156, "Group Morning Run!", is the clearest early answer because it turns Li Bao's situation into a concrete plot event.
Chapter 137, "Lai Fu's Death Has Another Cause", is the clearest early answer because the violence around Jiang Li becomes final instead of hypothetical. It opens with Jiang Li personally went to Lai Fu's tomb and performed a small...
Chapter 187, "I Really Need an Apology", is the clearest early answer because it turns Apology During's situation into a concrete plot event. The chapter gives readers a real answer by opening on During the competition, she passed by him numerous times, unfazed by...
Chapter 44, "Laozi's Hands Are Made to Drive a Ferrari!", is the clearest early answer because it turns Laozi's situation into a concrete plot event. The chapter turns that into something concrete by moving from But the next move by the production team proved they hadn't forgotten...