Might there be any serious side effects for smoking weed the first time?

Unpredictable.: Some people tolerate cannabis fine while others have severe reactions. Possible effects of marijuana: anxiety, depression, fear, panic , delusions, hallucinations, losing touch with reality, inattentiveness, short-term memory problems, disturbances of thought processes. Fatigue, poor concentration, slowed reaction times & slowed problem solving.

Addiction.: You could easily become addicted,,and then move on to harder drugs and create a lifetime problem for yourself. Don't start down this destructive path.