Weed Question

Take up the offer, I mean why not? One puff isn't going to kill you and at most you're going to cough a little since you're a smoke-vergin pretty much.
Make sure you have fun, go there light-minded and don't forcefully even expect to get super high on the first try, everyone reacts differently and in some cases people don't even feel it. Remember that obsessiveness is the bad thing, if you really start smoking weed on a normal basis just make sure you don't do it too often as that can and will cause you medical problems in the future. A good thumb rule would be once a week since it's not too much time from one to another and you don't take too much overall.