Welcome to Backyard Chickens! Thank you for joining- we hope you have a good time here. It looks like you have a handsome Blue Cochin cockerel. For the size and age... the comb is a little too large and bright. If it was a she at egg laying stage and had a bright comb, I'd have said pullet. In this case, that's probably a cockerel.
I've had two roosters together in the past, they went through the 'teenager' stage together... but fought when older without developing a hopeful pecking order. Depending on how they were raised, and if together, it can vary. Time will most likely tell. Just have an extra water and feed station- have enough perches- and it's the best you can do.