This is a great question. I would zoom out and think more holistically about how to approach career advice and what I tell people looking to get into Product Marketing overall.
I usually approach significant career transitions or moves in two-steps. Sometimes, people see the next job and say - I’m a content marketer at a startup - how do I get into PMM at Uber or Google? Sometimes you first have to get into PMM, then, you have to move over to Google or Uber in PMM.
Same approach for B2B vs. B2C approaching in two steps. In general, I actually think great PMMs are audience agnostic, and most of the frameworks / principles are similar...Yes, there's some ramp up time, but each discipline has their own super power.
B2B has the challenge of working indirectly through sales to get the message out, so you really need to rely on influence and creating assets that others will use, but I usually see a bit more of a growth/funnel focus from B2B folks.
B2C PMM typically need to bias on Product + User Experience, and telling emotional and compelling stories. The best can bring both sides to the equation. If you’re in B2B now and want to move over, I would start by trying to get closer to the Product (focusing on user and customer experiences) and focus on crafting great stories. Even if you’re not launching splashy campaigns, great marketing is still great marketing.