For me I started seeing my beard appear within 3 months. But my family, particularly my mom's side, are little hairy beasties (everywhere but the head -- go figure, I haven't lost hair yet there but am tempted to shave it and leave the beard). If you have a cisgendered male brother or uncle to talk with ask them how it grew in. It tends to vary.
I've gotten a lot under my jaw line, a bit more along the jaw and a fuzzy mustache. The last is the one that seems to be taking the longest to come in. I believe it will take about 4-5 years for the full masculanization of T to have an effect.
ETA: as far as hair colour goes, mine has been odd. My family is all dark brown-black hair and we go grey early 40s is the start). My beard has been predominantly dark brown with a few reds (and I mean RED) and a few grays. Go figure.