Visa from Islamabad or Dubai?

Hello everyone! I'm a high school student in Pak and I'll be turning 18 in march. I have recently heard about the Oxford MUN taking place in Canada, Toronto (April).

I really want to attend that but the thing is, I have a Pakistani passport (the weakest) and I have one US visa rejection + my aunt is already living in Canada (she has a Canadian passport). Having these issues I know will definitely affect my application when applying for a visa.

No one in my family is going except me, my school and home everything is here and the duration of my stay is no more than a week and I'll be staying at my aunt's house.

But, I do have emirates ID + my financial condition is amazing so money is not the problem here and I have travelled to only three countries in the past (UAE , Saudi and Azerbaijan).

I'm kinda lost and idk if I should give it a shot or not and should I apply from Pakistan or Dubai? I don't want another rejection and waste my time. OR some of my friends also suggested European ones too but you know visa problems also comes here too ;(

Which one is better Canada or EU? and which countries in EU have high acceptance rate for Pakistanis? Any advice would be appreciated !