If you're unsure which side of a path to be on especially with shared paths default to the national driving side.
Bonus if you hear a bike bell don't jump to a side or call your dog into their path just keep doing what your doing
The bike thing is real. So often I hit my bell or call out “on your left” when about to pass people from behind. About 50% of the time those people immediately move to the left, which is why I always try to indicate far enough in advance for them to get in my way, realize their mistake and move back before I catch up to them .
The only people that keep doing what they were doing when I call behind them on my bike are the ones that are walking in a group side by side blocking the entire width of the pathway...
I'd suggest not calling anything out. People may well not hear exactly what you said and, even if they do, are unlikely to be able to process the information quickly enough. They'll end up guessing what to do and that will often result in them doing the 'wrong' thing.
I never call out or ring my bell, and it works great every time. Except then people get pissed for some reason that I didn't ring my bell? No idea why they care, I'm not going to hit them.
If you're in a country where most people don't drive, don't expect this to work well. Japan seemingly has no system (though people in most of the country will probably move left most of the time). It definitely takes some adjusting to the chaos of everyone walking wherever the hell they want.