In general, converters are not a great idea. You want dual-voltage things so all you need is a plug adapter. Most electronics are dual-voltage. While I'm not 100% sure, I think all those countries use the plug adapter with two round prongs.

On another note, hope you have MANY days for that many countries!

UK has three prongs, two flat and one vertical. France, Germany and Netherlands have two round pins, and Italy and Switzerland (southern Europe, including Rome) also has two round pins but slimmer, and a raised profile on the plug. In my hairdryer kit bought in Europe I have an adaptor for all of those. Have a look at this website; Korjo is an Australian company so it makes plugs for the Australian market but it gives a picture of just about any plug it sells so you can see what you are aiming for. Plug in a name and you will see the corresponding plug:
https://www.korjo.com/adaptor-guide/...ry=switzerland

Instead of buying many plugs, if you go to a luggage shop you may be able to buy a universal adaptor which works for all European destinations. I have one from the 1980s and will rue the day when it finally dies, but if you can find one they are great.

Lavandula

There is a universal adapter which will cover all of Europe and the U.S.

Plug converters are also being converted. Official French plug now is two-pronged, but with a hole to accept a third tine sticking out from the wall socket (for grounding). British three-pronged plugs have a different shape and alignment of tine. In some countries such as Italy, older plugs will fit; sometimes not. And so on.
Lots of sites on the Internet provide picture guides. Better to find a comprehensive one for yourself. Meanwhile you can also check the fine, often dark, print on your gizmos to see which amperage is required. Roughly, it's 110 for North America, and 220-240 elsewhere. Can't comment on Caribbean requirements. Most, these days, can be switched or do it automatically.

A warning, though; North American hair blow-dryers are around 110 can be switched but at 220-40 will only run at low.
https://en.wikipedia.org/wiki/Ampere#Portable_devices

Another warning: Some cheap all-purpose plug converters, which unfold like a puzzle, use plastic tines for the ground. No protection there at all.

Take a universal plug adapter and a short power strip/extension lead so you can charge multiple things at once. That way you only plug the power strip into the adapter and can use your normal plugs in the power strip.

Here's the adapter I use, lacking the neutral for England, but then not having a neutral of the U.S. The rest of Europe may have the ground built into the female in the wall.

Should I buy in Europe? No, you may not find adapters that suit your home plugs. Buy a set at home.

Should I buy a converter? Not for tech equipment, computers generally have a built-in capacity to work no matter where you are. Hairdryers are the biggest problem, and some even have the ability to turn a switch to change the voltage. So if you don't have a hairdryer then don't bother. Many hotels provide a hairdryer nowadays anyway.

Lavandula

No reason to take a hairdryer these days, especially if you're on a tour. The hotels will provide them.

All electronics should be dual voltage - read the label. If you are going to multiple countries a universal adapter is probably the best bet.

If that's a tour it sounds like you will be moving too fast.

Depends on what you are interested. Are you more a big city lover or countryside?

Use the chargers that come with you phone, tablet, camera or whatever. Get plug adapters that you will need for each location. Many have recommended the universal type adapter, but check each one out carefully. Sometimes they are so bulky and heavy that they sag out of the power outlet and will not stay "plugged in".