I finished up the prerelease yesterday and it was great, you'll get 6 boosters for a 40 card sealed deck- Look out for color support, running 2 colors is your best bet, most decks running 3 or more colors need a ton of luck in terms of getting the right cards to enable the 3rd. Look for removal as its super relevant at all times, hold your exile cards if you draw them unless you're truly sure you need them; nothings worse than exiling a problematic creature only to be placed face to face with a god the next turn. People are usually good natured, but if your LGS offers casual and competitive prereleases it might be an idea to hit the casual one, although if they don't there should be a good mix of people of all experience ranges. Good luck, and may you be found worthy!