Trying to build muscle but my arms looks like skyscraper instead of bull leg.

I am trying to build muscle and I am a mega-beginner. I started a few weeks ago and my arm(short biceps) rised like a skyscraper. I didn't expect that and I don't know much about bodybuilding. And this is not good because my arm is being pump after training and grows on the y axis. Not x. But I want my muscles to expand. I tried working for triceps and my arm's back(whatever is there). But I couldn't make it. Is this normal? Which exercises should I do? I know this is ironic but there is no way I know. Thank y'all for helping.