When i record vocals they only register on one side of headphone, while everything else come from both right and left- is there a way of having a single microphone send the signal to both side ?
Personally on my sound card when I monitor (it has it's in-built mixer), if I record on channel 1 (left of 1/2), I will only hear it on the left channel and if I record on channel 2 (right of 1/2), I will only hear it on the right channel of the output.
Choose the right input on your track. You have probably Stereo left/right or something. You should have mono left or mono right, you will notice which one is right. Then your track becomes a mono track and you hear it in both ears! ( Most mics are mono )