Some folks do keep roosters as pets.. Even more than one and together! They're great animals when they haven't gotten the wrong message and also when they aren't tasked with having to be protective. Some are great even when tasked with protection but it usually helps if they were brought up in an older flock.
Are you allowed to have roosters? Or thinking about keeping him? Also, what are you feeding him? (layer feed fed long term can cause issues to those not in lay)
Usually a single chicken regardless of gender is going to be a lonely chicken as they are very much social flock animals.
I personally would NOT add in a single hen as she will *probably* face over mating with a young virile cockerel. There are a multitude of possibilities on how to move forward.. depending on what your specific goals and needs are..
Craigslist farm and garden section is good place both to rehome or to acquire fresh additions. Buyer beware, KNOW your location.. many illnesses that effect poultry don't present right away and could take down an entire flock. Highly pathogenic avian influenza is currently effecting several parts of the US.
FWIW.. pecking at you is NOT aggression.. it could simply be grooming/getting bugs off you.
Early aggression looks *more* like dropping a wing and dancing
at you.. or quickly running up from behind and pecking with a rapid retreat that makes you wonder if that even happened. Confined spaces might see a frontal attack.
Best wishes!