Attending conferences as a first-year undergrad
"keeping up-to-date with recent advances aren't really applicable to me..."


Not so; that's a myth. Your poster got accepted, and that means you are now part of the "recent advances" in the field. 

So, go. Tell people what you are doing. No, people won't flock to your poster and ask for your autograph; however, chances are, someone there will find your work interesting. You might get to talk with people who have done similar work. You might get a few pointers. You might get some affirmation that you're working on an interesting problem. 

I went to a conference once where I was just starting out in the field. One of the world's most renowned experts attended my talk. Imagine my surprise when, a year later, my advisor returned from the same conference, he told me that this same expert approached him, and asked, "Where is that student of yours? I really liked his idea..."

You never know what kind of benefit you might get over the course of a few days when everyone there shares expertise in some common interest. Sometimes it's someone who can help you out, or nudge you in the right direction, or motivate you, or challenge you (hopefully in a constructive way), or merely encourage you by nodding their head as you speak, seemingly interested in what you are doing.  Maybe you'll end up with a business card and a contact number of someone who can help you down the road as your research progresses. 

Likewise, you stand to learn a lot from them, too. Who knows? Maybe someone will light a spark that will ignite a passion later. 

By the way, most people like talking about their own research. So, if you attend a session that interests you, but a lot of it goes over your head, try to sit with that speaker at the lunch table. I'd bet that, more often than not, he wouldn't mind explaining some of the fundamentals to a bright and curious student.

Maybe I'm being overly optimistic, but I'd bet you'll come back a bit more rejuvenated, somewhat more enlightened, and a lot more encouraged.