There's is good advice here.
I'll add my 2 cents as someone with decades of real martial arts experience. What I tell people who ask for self defense advice is don't be a victim. The goal is to make a would be attacker realize that it would be "expensive" to take you on and that they should move on to easier targets. Mostly, this comes from how you carry yourself. Head up confidence but that doesn't mean acting like a dick. Some people get that confused. Most bad guys aren't all that bad. But if you meet a real killer then good luck to you and run.
If you carry a weapon plan on using it or having it used on you. That goes for pepper spray too. Martial arts classes can give you tons of confidence but many dojos teach point sparring and magazine techniques. Not really useful in the real world. But the way you carry yourself afterward is often enough to keep danger away.
Given all that, I've been all around this world and never had to run
. Just a couple of minor situations that were managed but the real truth is that most people are really cool. Enjoy your trip and make a lot of friends.