We use basic Tascam studio recorder...
Is it stereo or multi-track? What kind of instruments/music? What kind of microphones? How are the acoustics where you are recording?
...but we are hoping Audacity could really help clean up the recordings.
That really depends on what's wrong.
There's really no substitute for starting-out with a good recording. Even with modern professional software, pro recordings are still made in soundproof studios, with good mics, good mic position, good acoustics, and good low-noise, low-distortion, equipment. (Plus, good talent and good instruments.
)
It's probably best to start by adjusting the volume. You can use the
Amplify effect to adjust the whole file and you can use the
Envelope tool to adjust and/or fade-up/fade-down various parts of the recording.
Professional recording/mixing engineers use quite a bit of dynamic
compression. Compression evens-out the loudness by making loud parts quieter and/or quiet parts louder. In practice, it's often used to make "everything loud" without introducing distortion. If you over-do it (and many modern recordings are over-compressed to make them as constantly-loud as possible) you kill the dynamic contrast in the music, and the music gets boring.
You can experiment with the
Equalization effect to boost/cut certain frequency bands. This can help if the recording is "too dull", or "too bright", or if there's not enough bass, etc.
Reverb is another common effect. If you are not recording in a room with plenty of natural reverb, you can probably benefit from some added artificial reverb.
There is a
Noise Removal effect that works by feeding-in a "noise fingerprint" (a sample of noise-only), and then it tries to subtract the noise from the signal. Noise reduction works best when there is a constant low-level background noise. If the noise is bad, noise reduction can make the recording sound worse.
When you're done with everything, it's a good idea to run
Amplify (or
Normalize) to make sure your peak levels don't go above 0dB. Do this after processing, but before saving. If your peaks go over 0dB and you save, you can get clipping (distorted flat-topped waves).