Originally Posted by Guybrush

If you do that, you won't hear the mic. Or at least not until you turn it way loud and get lots of noise in the signal. Certain audio like mic and instrument level sources need to be amplified before you can use them as line. So for a mic to get connected to a line-in, it should pass through a preamp first.

Mixers and audio interfaces have preamps in most of their channels (just not in their aux/line ins, midi ins, spdif etc). Some mics, like the Shure SM7B, might need a lot of preamping (upwards of 70db) and more than what a typical audio interface or mixer can give, so that might be another thing to be aware of (although condenser mics are generally good in this regard).

About the Yamaha MG10XU, I have one of those I believe, just slightly bigger. I like it a lot as it's cheap, sounds fine and has compressor on the channels to f.ex. keep vocals a little more level. I've actually never hooked mine up to a PC through USB and recorded with it that way because I prefer an audio interface, but it probably works fine.

By the way, note that condenser mics also need phantom power (power through XLR cable). Like for a mixer, just check how many channels have phantom power.