>>45455
Technical post ahead:
The noise floor is a characteristic of every electronic device.
Since I have not listened to the recording, I cannot say for sure, but in most cases, if you have spoken clearly enough and close enough to the mic, either the preamplification of your digital mic is insufficient for your use case, your analog mic doesn't have a high enough sensitivity for your input device and needs a separate preamp, or the microphone needs phantom power. There are other options, but those are less likely.
If it was a ground loop over USB, the noise would probably change as you use the PC in different ways. Wind noise and bad power supply design often result in a deep hum. The latter can be avoided by using the capture devices on battery wherever possible (battery powered laptop/preamp). Also PC, AC and other cooling fans are often ignored by our ears after some time but can still be annoying in sound files.
Lastly, you want the signal to be as loud as possible from the initial capture device onwards and throughout the hole signal chain while still allowing for sufficient headroom (claps are a lot louder than normal speaking) and without overdriving the input on any device.
The easiest way to achieve all of this is with an at least mediocre USB mic with, if needed because of noisy USB power, an external power supply.
The Blue Yeti mics have a pretty good recognition among streamers for being easy to use and having a relatively good sound quality. I've never used one though.
Actually as I look at reviews the Rode NTUSB seems to be the better choice for the price (at least in the EU).
tl;dr
Get a large, high quality USB mic (like a Rode NTUSB) if you want simple, high quality recordings.