No matter what you expect from it before you go, your wrong.  Not wanting to be mean lol, but its just impossible to know.  Its like trying to describe being high on weed to someone who's never smoked, words can't do it justice.  (this is just an analogy, DMT isn't like weed.)

I was very nervous my first time through too, just important to start out wish small dosages and work your way up like slowly. It's definitely not for everyone, and it'd be easier to realize that on a just past launch trip then a flying out of your body or breakthrough type experience. 

I'd say that it is definitely a great time for me 85% of the time or so, all glowing fun positive experiences, but there are the 15% that are darker or negative.  Just something to keep in mind. 

If you want to, go for it.  My life's never been the same since I went my first time, and I wouldn't take that back for the world.  Its amazing, crazy, and whatever you experience while your on it, it will definitely pull you out of your box and shatter a couple of preconceived notions of things. 

Best of luck