is it okay to use two nano sim cards in my iphone 11 canada variant? Can i change my sim card tray?

You cannot. North American iPhones do not support a second physical SIM card. They have one SIM card reader and one embedded eSim your can use with supported carriers.

Changing the tray will do nothing as there is no actual hardware to read a second SIM card in the iPhone.

You can “swap” the hard-SIMs … but you can’t install both at the same time.

“Dual SIM” means 1x hardware slot …

… and 1x Embedded SIM (eSIM) which can be electronically provisioned by your carrier “over the air”

More details are at link in “Related Article”