Capturing & decoding USB3 at the signal/waveform level requires high-end equipment. The bitrates of USB3.x are 5 Gbit/s or faster, which would require at least 10 GHz or faster sample frequencies. There are other ways to capture USB3 at the bus/wire level, but it still requires specialized equipment that isn’t cheap (e.g., a USB3.0 protocol analyzer).
If you just want to capture the data packets, you can use Wireshark and Wireshark’s USB capture feature. It won’t see everything at the bus/physical level, but it is ‘free’ with a PC and some open source tools.