Some essentials that are in my purse while traveling:
Wet wipes. This is KEY. I cannot stress how important wet wipes are when you travel. Seriously, they're like a $1.50 a pack at Target. Always better safe than sorry!
Coin Purse. I JUST bought one from my favourite brand and am obsessed with it. You can find cheap ones on Amazon- I've added two options below that might be good options.
Cash on hand in case of emergencies (obviously in the currency of the country you're in).
Earphones. Although I prefer bluetooth earphones on a given day. I don't like having to remember to charge them all the time.
Portable/Travel Charger. You're in a new place and you're probably using your phone to navigate and end up draining your battery a lot quicker than the day ended. I hate being in situations where my phone is dead because it just makes me feel like I'm in a vulnerable spot so I make sure I always have it on me and that my charger is always charged (heh) especially because I travel alone a lot. I've also added a link below for a charger on Amazon!
Credit card. I always have my travel credit card, which allows me to use it without any foreign transaction fees.