Most travel power problems come from mixing up two different things. An adapter changes the shape of your plug so it fits the wall. A converter changes the voltage. Most people need the first and not the second.
Check your chargers before you buy anything. If the label says input 100-240V, 50/60Hz, the device handles any outlet in the world and only needs the right plug shape. Phone chargers, laptop power bricks and camera chargers almost always say this. The United States runs at about 120 volts, while most of Europe, Asia, Africa and Oceania run at 220 to 240.
The first adapter is a universal one, a single block with sliding prongs for the major plug types. In the US you use Type A and B, the two flat pins with an optional round ground. Most of continental Europe uses Type C, two round pins. The UK, Ireland and Singapore use Type G, three chunky rectangular pins. Australia, New Zealand and China use Type I, two angled flat pins. A good universal adapter covers all of these and saves you from buying a new one for every trip. Look for one with built-in USB-C ports so it doubles as a charger.
The second is a small, dedicated adapter for wherever you spend most of your time. Universal blocks are bulky and can sag out of loose hotel sockets. A cheap single-country plug is lighter and sits firmer in the wall.
The third is not really an adapter at all. It is a compact multi-port USB-C charger. Plug one of those into one adapter and you can charge a phone, earbuds and a laptop from a single outlet, which matters in hotel rooms that seem to have exactly one.
What you should not pack is a hair dryer, straightener or other heating appliance marked 120V only. An adapter will let it fit the socket, and 230 volts will then burn it out. Those need a proper voltage converter, and it is usually easier to use the one the hotel provides.
The short version: read the label on every charger, buy one universal adapter with USB-C, add a small plug for your main destination, and leave single-voltage heating appliances at home.
