Casting on with super bulky yarn

Hi, All. I am about to begin my very first knitting project, a baby blanket for my first nephew coming soon. I have Bernat Baby Blanket yarn which is super bulky. I have to cast on 84 stitches with a 8mm circular needle, so how much yarn do I need to allow on the left side?

Hi and welcome! Wonderful news about the new nephew.
I’m not sure that I understand what you’re asking about yarn on the left side. Is this yarn to measure out for a cast on like long tail cast on?