AnimeNEXT convention help? Has anyone been to one?

I found on the internet an animeNEXT convention coming up where I live. I've never been to a convention before, so I'm not sure about what to expect. Do you have to be in cosplay to enter, or can you come in regular clothes? I'm not into entering any events, just watching them, especially the Masquerade (I've viewed some on Youtube). My friend is coming with me and we both have the event planned out. Is it extremely crowded to the point where you have to etch your way to different facilities (like a concert-crowded)? It would be great if anyone whose BEEN to these animeNEXT events could give me any info/advice. Tell me what your experiences were like so I can get an idea. Thanks in advance.