Tekko! <3 Tekko is small, so it's nice as a first con. (The first one was my first con, actually. I'm such a newbie. Aww.)
Program book. Read it. Go to whatever strikes your interest. That's about it. Be courteous and considerate - don't talk through screenings (hello guy next to me in the 2005 AMV screenings I hope you never come back), push or crowd out people in the dealers' room, or block hallways if you can help it. There are a lot of people in a very small area and half of us are sleep-deprived. Be part of the solution, not part of the problem.
You'll probably wind up standing in lines a few times, so bring something to read / a handheld game system of your choice / some friends who aren't going to want to kill you after three days.
Eat something. This is a convenient con for that because the mall's food court is right across the way. Not exactly classy, but convenient, especially if you're a chibi-otaku on a high-schooler's budget. Also sleep. And drink water. And bathe. They tell everyone that in every program book, but do they listen? Noooo.
The
Tekkoshocon forums seem really close-knit and are probably quite helpful if you have specific questions.
Have fun. And FYI, it's the last day of March and the first two days of April.
And buy stuff from the Artists' Alley people. ;P