Question about electronics/adapters

I will be going to London, Paris, and Rome in October. I'm trying to figure out what I need to get and I figured I'd ask on here because I bet a bunch of people know about this stuff! I don't know squat about this sort of thing so any information would be helpful!

Devices I plan to bring: Laptop (MacBook Pro), iPad, iPhone, Nintendo Switch, 2 portable chargers (1 charges with micro, 1 charges with USB C), and my hair straightener - link to straightener for reference. Additionally, I have an extension cord for my laptop that has a 3 prong plug on the end. Can I use that or do I need to switch it back to the 2-prong attachment without the extra extension?

What do I need to get as far as adapters/cables/etc? Typically I charge my phone by connecting it to my laptop. I know I'll need some adapters, does anyone have any recommendations? I went to Italy once when I was 15 and my straightener then got fried, my dad said it was a voltage issue but didn't know more than that. Thanks in advance!