I tried shrooms once, and I was kind of in your position. I was in portland urban RVing after driving to mount hood for the summer, and we managed to get enough for me and my friend. I was a little hesitant because I had never done any drugs harder than weed, but I ended up having an incredible time. My good trip was due to

resence of friends who I both trusted and got along with extremely well-Good mood prior to taking them-No bodily pains or aches-No responsibility at the time -warm weather (ie comftorable)
Because of these conditions, I had a fantastic time. I took slightly less than an eighth just because it was my first time, and I still tripped pretty incredibly.
For the first part of my trip, I was not terrifically functional. Not that I was disfunctional, but my attention span was short and I was too fascinated with everything to remember where I was going. I got lost for like an hour, and even though I wandered into the hood, me and my friend were picked up by our other friends in our winnebago and everything went fine. I tripped late into the night, and after going into downtown portland, I had a few close calls crossing the street. If your going to do anything where you might possibly get hurt, make sure you have a sober friend to keep you in check and happy.
I wouldn't necessarily trip at night, but apparently I'm not really afraid of either night time or hobos, so those things didn't really affect my trip.
I smoked weed and ate a vitamin c packet before tripping, and it was pretty awesome, but increases your disfunctionalness slightly.
I had an exhausting mental session. By the end of it I had pondered like every aspect of my being. Very cool drug. Does great things to perception and you learn a lot about yourself. I suggest it if you are the kind of person who doesn't have enough insecurities to worry much during a five hour period.