New to Montréal this Autumn!

I'm arriving in Montréal from Ireland on a two-year visa this October - I've lived in the Greater Montréal region before but this is my first time living in the city, and the only person I know there is my Quebecois boyfriend!
Hoping to branch out and meet fellow like-minded travellers, if anyone has any advice on the best way to do this in Montréal then please let me know :)
I have diverse interests and wouldn't be shy about signing up to extra-curricular groups etc.! I'm a Journalist though, so my hours can be irregular.
Any help very much welcomed!