i’m 16 and smoke 0,3 g of weed every month can this be bad for me in any way?
could well be. your brain is still developing. i would at least cut down.
There’s some interesting info about the possible effect on mental health in this report if you haven’t already seen this: Why is medical cannabis so hard to access on the NHS?
Apart from that any kind of smoking is bad for your health anyway of course.
Personally if you could do without it I would. You might want to ask why you are bothering with it and try to find something to do which would be more beneficial to your future wellbeing instead.