car not starting no crank

[3.7 slp]

Of all days t happen yesterday Christmas day. Went to start to old girl and just got a click. The electronics where All fine and lights went out on the dash as they should. Tried the key and push start and just the same.
Then gave it 30 mins and now starts fine. Not sure if it may be cam or crank sensor. We anyone have any where to start looking at. There was a code (strater motor not tturning) can not recall the code.

Any tips would be great
thanks all