A:AnswerYes.. it's pretty easy, just open the battery compartment on the bottom of the camera and the SD slot is in there.. you don't have to take the battery or anything to add the SD.
A:AnswerYes, there is a power adapter for the M50.
Canon EOS M50 AC Coupler Charger Kit
It includes a different battery with a connection available in the battery compartment. There is a small rubber piece on the battery compartment that can be opened to allow the connection.
A:AnswerThat should be plenty of space, unless you plan on storing your vlogs long term on the card itself. I use two 256GB cards, but that’s just to stay on the safe side.