I was wondering. When im recording several tracks, is it possible to play the others while recording a new? it would make timing way easier when recording several layers.
Also, why are the effects grayed out even when a track is selected?

as for your first question, yes, go to: Edit > Preferences > Click the little box next to where is says "Play other tracks while recording new ones" > OK

-Dan

Audacity should have that ability by default, however, I did once run a version that would turn that function off by itself at random. The above post contains the instructions to turn it back on. Figured I'd mention it in case yours does the same thing.

Also, why are the effects grayed out even when a track is selected?

Be sure that playback is stopped when trying to apply FX to a selected region. Audacity doesn't do FX in realtime.