Hello! This isn’t a personal question at all, and you’re actually the second person to ask it (so this answer will apply to the Anon who asked, as well).
My sister-in-law and I arrived at the venue approximately 4.5 hours before the doors opened for early entry (6.5 hours before the first band began); in retrospect I can say that there was no need to get there that early to be near the front, but it was what allowed us to be directly in the front row. However, that venue was much smaller than the ones on the M&S Canadian tour, so perhaps you should plan to arrive a few hours early if you’d like to be in the very front.
Thanks for the question. Please let me know if you get in the front and I’d love to hear about your M&S concert experience. I don’t know if it will be your first time, but I do know that it will be incredible! :)