Time delay between tracks

I have only used Audacity for 2 days so this question might be very basic.

I have imported a wav file with some backing music and try to sing in a new track along with the music.
When I play back the two tracks together there is a time delay between the tracks. Is that normal?
How do a get rid of it?
Is there a command where one can syncronise the tracks.

The same happens if I record a guitar track and sing in a new track.
The two track are not syncronised.

I have notised that one can move tracks along the timeline but it is a lot of work to make the tracks sound right.

I record from a mixer where my mic and guitar is plugged in and I have USB connection between the mixer and the laptop

[u]Latency test & latency compensation[/u].