Converters

Mary, Do you mean voltage converters or do you mean plug adapters?
Converters convert European 230V electricity into 110V. Plug adapters just solve the problem that the plugs are different shapes.
Most modern electronic appliances (phone chargers for example) are labelled "110/230V 50/60Hz AC" and DO NOT require a voltage converter, just a plug adapter. If any say "110V 60Hz AC", then you need a voltage converter.

Two questions:
1) Read the label(s) on all your appliance(s). If they say "110/230V 50/60Hz AC", you do not need a converter, just plug adapters.
2) Do the plugs on appliances have 2 or 3 pins? That decides whether you need a 2 or 3-pin plug adapter.

What are you charging?

Most USB "chargers" are actually voltage converters. They convert 100-240 VAC input to 5 VDC output. They often have a wired connection to a USB Micro plug (the type that fits into most non-Apple phones as well as other devices).

The USB chargers are usually double insulated, non-polarized devices with only two blades of equal width. A simple Europlug adapter can be used to plug into receptacles all over Europe. You can actually purchase USB chargers with two pin Europlugs already built-in on Amazon and omit one loseable thing to take with you.

Starting point of your discovery voyage is reading RS travel tip: https://www.ricksteves.com/travel-tips/phones-tech/electric-adapters-converters

We're looking to charge electronics....laptops, iPads.

2 plug adaptors is what I'm probably asking about.

Get a cheap 2-plug adapter then. The ones I use for Croatia also work in Germany.

https://www.power-plugs-sockets.com/ca/croatia/

In Croatia the power sockets are of type C and F. The standard voltage
is 230 V and the standard frequency is 50 Hz.

See web link for images of plugs and socket.