It can. However, usually when one smokes for the first time they experience not so pleasant effects, or some even report feeling nothing at all. The first few times I smoked, I did not like it and I experienced a headache. I was dating a boyfriend at the time who smoked a lot of weed so after my fourth or fifth attempt I started to really enjoy how it made me feel. I developed a medical marijuana weed habit for about a year. I stopped smoking cold turkey eight months ago, and the only thing I have now is a cough that still won't go away.
Yes it can calm you down, it can also make you sleep easier. However I stopped smoking it because I started getting paranoid and panic attacks after I smoked. I ended up shaking in bed under the covers, it felt like my body was shaking from being cold but I wasn't even cold, I was just freaking out and my teeth were chattering. I got good weed from a medical marijuana dispensary so its not like it was laced, either.
Just be smart about it and only use it sparingly, start with just a little bit, and don't develop a habit of it. It's an expensive habit.
By the way I could never smoke around other people because I would end up getting really quiet on weed, I only smoked by myself.