Since: Dec 04, 2007
A couple questions, are you getting any signal at all from the Mic into the mixer? Do the mixer's meters light up when you speak into the mic? Do you have the Mic 1's gain knob turned up a bit? Test each part of the signal path, and make sure everything's good there, and then we can look at the computer settings as well.
Just to double-check the path, The mic (C-1 Condenser mic) Should be plugged into the XLR (mic 1) input on the mixer. You'll want to make sure the mixer's phantom power (+48v) is turned on. Condenser mics need that +48v on the mixer preamp. The mixer's main output (which is typical 1/4" stereo jack) Should be using an RCA adapter and going into the L/R inputs on the UCA 202, which are RCA inputs.
If the mixer and the interface check out okay, then check your computer settings and make sure the UCA is the default under your sound options in the windows control panel, and make sure that you have the UCA selected when you record into audacity.
Beyond that, check the mic gains on the mixer, and the input gain on the interface, check the tracks in audacity, make sure they're routed properly to the UCA inputs.
Hope that helps! Oh, and Welcome to the forum. :)
Edit: On using both mics: there's probably a way to do it, but in my experience a DAW, or recording software like audacity, will usually use a specific interface (like the UCA) and you'll route your tracks to that interface. I'm not sure if you have the UCA set up, that you'll be able to use the Samson concurrently since it probably uses its own interface/driver, which may or may not need to be selected in Audacity. Granted, you can always record into one, then switch and record into the other, but I don't know if you'll be able to use both simultaneously. There may be a workaround to that somewhere though.