Student or Learner
Is this sentence correct?
It is about ten months to their 1st wedding anniversary, Mary and John have decided to book a trip to Australia to celebrate the occasion.
I would change "to" to "until". You need either a semi-colon, or a full stop and a new sentence, instead of the comma.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.