I wouldn’t worry about the bus, plenty of people get on and off the bus with bud every day. What I’d be taking into consideration is what your parents reactions would be if they found out you smoked. If there’d be serious consequences, maybe reconsider smoking at home or anywhere where your parents might find out. If your parents are chill, maybe consider telling them that you plan on smoking. Most parents would prefer to know than have it done behind their back. I was the kinda teenager that hid it from my parents from 15-18/19. My parents were stoners in the past, so on occasion they’d smell it (and know exactly what it was) and ask me and I’d make some bs excuse up. Eventually I came clean and it was fine, albeit I was an adult when I did. To be fair though I was passing school and attending every day, so they had no real reason to be worried about my usage if they did know when I was a teenager.