Hey guys, I am a very novice biker so please be a little understanding if I sound like I don't know what I'm talking about cause I probably don't.

I own a Canadian tire ccm excelsior 700 bike. I know it's gotten bad reviews but I've gotten three years and almost 2000k out of it. But now the BB is shot. I have a chance to by a Shimano BB SM-BB70 brand new for pretty cheap of kijiji. My question is will the shimano BB fit on the bike and what do I need to do to make it happen? I have to use the ccm cause I just had a newborn and the budget dosen't have room for a new bike.