Okay...I just did acid for my first time last night and I did 2 hits of paper. In terms of what to expect...don't expect anything...just go with what happens and if you start to panic or have an anxiety attack just remember a couple of things...1) Its only a drug, it will wear off. 2) Panicing gets you nowhere, stay calm and enjoy the trip. 3) RELAX, the trip is what you make of it and if you're flipping out your going to make things worse. Just remember you decided to do this and it WILL SURPRISE YOU...perceptions are changed and so is the way you think. So don't think that going into it your going to maintain your regular mindset or train of though...it truly turns your world upside down.
Pretty much my whole trip I felt slightly uncomfortable, but it was manageable. Wasn't really sure what I wanted to do, whether I wanted to stay put, go for a walk, talk to people...so I did a little bit of each. But I really think the most important thing is SETTING and PEOPLE...do it with someone you really trust to help you out if things go bad or not annoy you while your tripping...thats gotta be the worst thing.
Hope this helps somewhat...
PLUR!