as you've already done to an extent, coordinate with your roommate. (who will handle which bills? at what point should the person who's paying expect a portion from the person who's not? who will do which chores? what stuff should not be touched? who's getting the mail?)
get a spare key if possible.
clean up after yourself.
make sure you both know when the lease ends.
make as many bill payments electronic as possible. avoid signing up for snail mail. pay them on time; many utility companies will gladly charge late fees before finally shutting things down.
use this time to learn how to balance a check book. online statements work more often than not but sometimes people will overcharge for services and banks make mistakes.
if you can, book a meeting with a financial consultant to forecast what you'll be spending for in the future and how much you'll need.
buy some lysol.
stay hygienic.
do nice, unexpected things for your roommate so things don't get rocky.
keep an open mind. when you're out, you and your roommate will grow in ways you may not expect. be supportive as best you can.
before learning the nitty gritty from your landlord, assume you don't know anything about the fine print of your lease so you absorb as much as possible. if your arrangement is less formal, then this strategy will give you a greater advantage as you will be putting them on the record. (in fact, use a similar approach in most places or institutions where you're outnumbered. take advantage of every opportunity. knowledge is power.)
know how many guests you may have in your apartment and for how long.
avoid eating out. honestly, if you buy groceries from a dollar store, you can save a shit ton and still get a safer, more enjoyable meal than you would eating out. if you're an undergraduate with not much dime, you may want to keep this option open.
keep in touch with your folks on your own time so they don't panic and invade your space.
lock your doors and keep your shit locked down. keep your local area connection password protected.
you'll be able to find an app for just about anything. (finding the cheapest gas in your area, keeping track of your online bank statements and balances, locating public transportation, etc.) take advantage of these tools. they make life very easy.
buy some chairs, a coffee/breakfast table, and a bed if necessary. before spending on anything bulky, ask family members if they have anything to spare. you're going to want at least a week worth of towels / wash cloths. ~10 sets of silverware / dishes. how much you need depends on how much and how often you're willing to wash them, so get a few extra of most small items that could be lost or damaged.
most importantly, have fun!!!
i wish you the best.