I smoked less than 30 times in my 3 years in college. most of them being cbd pens and marijuana. i never purchased any substances but friends sometimes let me take a few puffs. am i at risk for lung cancer?

What you described would not raise your risk for lung cancer over your background risk. It would be prudent to abstain from tobacco, alcohol, weed and any other street drugs. Start exercising. Begin with low intensity exercise such as walking and gradually increase the intensity so that you sweat profusely. It may take a few months for the full effect. Get HPV vaccine. Wish you good health!

There is no conclusive evidence for lung cancer due to smoking marijuana at this point, but I do think we will see eventually COPID and asthma cases from frequent and excessive cannabis inhalation, and cancers are not out of the question. So, in my opinion, do not smoke or inhale any tobacco or recreational drugs. Good health to you.