Street Smart
A lot of people will tell you that there is no crime/pick pockets, etc. in Europe. It’s not because they did not experience it that it doesn’t exist. It does exist and it most definitely does in Southern Europe. Don’t forget, no matter how hard you try, you will stick out like a sore thumb. There are petty thieves just waiting to get their hands on your wallet. They often work in 3’s so one will distract you (scream, bump into you, etc. Anything to make you look away) at that moment the other will try to put their hands in your bag. I actually caught a woman doing this to me once (in Aix) and I saved myself. I couldn’t believe it, I can still see her hand so smoothly reaching into my bag to try and grab something. It does happen. The best thing is to carry a bag which is in front of you and firmly closed. Put nothing in your back pockets and keep your phones in view or even in your hand held tight. In today’s world, we barely need cash, so I would have only the cash you need (often markets want cash but even many of them accept cards these days), your keys and ID. In fact, I can now use Apple Pay just about everywhere. There’s usually an ATM not far if the vendor insists on cash but it’s rare today. You really don’t need anything else if you’re out and about.
I wouldn’t be worried, I would just be sure to be properly equipped. The most vulnerable places are the underground trains and tourist spots. Less is more.