Too late now but get into the habit of checking “Do xxxx citizens needs a visa to go to xxxx country”. When I was getting my Brazilian visa (pre Olympics) there was a guy there who somehow got on the plane to Brazil and was immediately sent back because he didn’t have a visa.

It’s crazy how much business is conducted abroad over WhatsApp. I’ll book and tour and they just text you where to show up at what time on WhatsApp and I swear I’m going to get ripped off but I show up and it goes as planned.