For the record a half eighth usually gets me trippin balls and a full eighth usually fucks with me, but everyone else always says that its not enough for them so I don't know if I get good shrooms or I just get easily effected by them or whatever. I've done shrooms probably like 7 times over the years and usually always took a half eighth and never once did not trip.
Smoke lots of weed as you are waiting for them to kick in to help with nausea/just to chill out and not get too anxious.
Wear sunglasses if you go out in public because your pupils will be dinner plates.
Try to be outside for most of the trip, but stay close to home while you are peaking so you can retreat if it all gets a little too real (I've passed out before during a particularly intense peak and it was at the campground of a national park so it could have been pretty bad). For sure be outside for the peak though, keep yourself entertained, and keep exploring.
My first shroom trip was incredible and seriously altered the way I looked at the world for a good while after, you should have a really good time. And if it goes bad, which it won't, just remember that once you get past the peak everything will be gravy and you'll still have like 5+ hours of awesome trip ahead of you.