Make sure you can crash somewhere, because it's no fun having to worry. Also, for your first time, don't drink because sometimes it can react badly. If you can, try to do it without a TV on or anything, just sit there with friends listening to music because you may have, as I did the first time, overloaded sensory information and may have an attack if too many noises and things are going on -- if it's good shit, anyway.

Is this your first time doing any mind-altering substances?