The issue you’re facing is that USB-A USB-B and USB-C are types of physical connector interfaces and not protocol specifications. In USB the letters are the connectors, and the numbers are the protocols (speeds.) In theory any connector can be used with any protocol. In practice the connectors have additional wires in some cases for the later protocols, so there are variants of them.
In answer to your question, that is a difficult problem. You pretty much have to know the specs of the device. The USB specification has theoretical icons that can provide you some info, but in practice they’re not to be relied upon, especially because they’re frequently missing. (This might be because of costs in getting the cables and ports properly certified.)
This is potentially a much longer topic that I could go on and on about, but to keep it focused, what kind of PC do you have (laptop or desktop), what’s the make and model #, and what Operating System are you running?
Answer those, and I can give you some suggestions for apps and methods to test what kind of devices a particular port supports.
My first USB-C phone, a Google Nexus 5X, has USB-C combined with USB 2.0. My current phone has USB-C with USB 3.0 and uses USB-C charging, which means I can plug it into my laptop docking station and charge it quickly. USB 2.0 devices had a very limited capacity or had to use different proprietary chargers to get quick charging.
I’ve also had slower (USB 2.0 and USB 3.0) USB-C based dongles for things like smart keys and memory sticks.
As @PHolder and @LaughingMan say, it is a complex subject. But all of the PCs I’ve had so far have been USB 3.1 with USB-C connectors.
The charging method is orthogonal to the data rate entirely. You can have a USB 2.0-only device that sinks 100W and uses USB PD to do it. You can have a USB 3.0 device that doesn’t use USB PD at all, and only uses the base 900mA provided by the USB 3.0 spec.
Your average USB PD charger, for example, supports NO USB data standard. Not USB 1.0, 1.1, 2.0, 3.0, or USB4… but USB-C chargers can easily support 100W power at 20V in an advanced way.
The power provided by a port or sunk by a port is a completely separate from what the data capability of the port is.
And try to figure out if the USB3 port you have supports video output is even more of a guess. Is it enabled in the hardware, are you using the proper spec cable for video over USB, is it some issue with a driver?
I had to do some digging but I found the full spec sheet for my PC. It is about two years old, and was buried deep on the HP website. The big problem while trying to locate the spec sheet was that Windows does not give me the full model number. The “About Your PC” section of Windows 10 give “xxx” for the last three digits. It does however give the full model number for the processor, and that is what gave way to finding the correct model.
Anywho, the wording they use for describing the USB-C port is “SuperSpeed USB Type-C® 10Gbps signaling rate (USB Power Delivery, DisplayPort™ 1.4, HP Sleep and Charge)” So, I am assuming @SamGreenwood might be on to something with the type of USB-C cables I have. I’m gonna order a cable that supports the “SuperSpeed 10Gbps” and let you all know what happens.
In the end though, the USB Implementers Forum has made this more complicated than it should be in my opinion.
Ok, so you run Windows 10. This is the best application that will tell you more about the USB subsystem on your computer.
It’s called USBView, and it’s part of Microsoft’s Windows SDK, but unfortunately is not installed by default on Windows systems.
It gives a far more detailed view of the USB topology on a Windows system than Device Manager, providing a tree view of the USB 2.0 and USB 3.x trees on your system, and important descriptors from every hub and device plugged into that tree.
Using this, you can help determine whether a particular USB port supports USB 3.x or USB 2.0 only if you use it with a USB 3.x thumbdrive, for example.