Listen to this while you read this:
http://www.youtube.com/watch?v=CVFscjOsPRA
If you have the balls to go for a meetup, go for a meetup before school starts, that way you can be they guy she goes to from day one of her fresher's week.
Instagram isn't much of a "social" network, it's more of what I call a "sharing" network.
get her on facebook, it's up to you how you will get her on facebook chatting with you.
From facebook, get her number...
This is the order i'd prefer, but feel free to go as you feel it should go; adapt to the situation, this i find is the smoothest flow.
IG>Facebook>chat>#(text>call)>SPAM>meetup
Don't sit around waiting for her to comment back, make sure you have some cool pics on instagram of you doing badass shit, or pictures of badass shit... just to demonstrate that you are of initial value. This isn't a necessary step, but it's something I'd do, don't start randomly suddenly posting pictures just to impress her.
If she doesn't respond then you can try again when she ups more pictures, don't overdo it, being social on a "sharing" network can come off as awkward if not done carefully. It is up to you how to progress on to facebook, from facebook it is far easier and smooth, I can't help you with that really.
When you get her number I like to use a funny variation of:
You: "Whats your phone #, facebook is too glitchy for me i'm getting off"
Her: "xxx-xxx-xxxx" (if she doesn't give you her number slow down, and keep building report and offering value, use the fact that you are a sophomore to your advantage.)
You: "yur a sweetheart, here's my number, xxx-xxx-xxxx, you can only use it for emergency purposes

"
Logoff. Don't text her, wait a few days for her to text you first, if she texts you first, she has more investment into you than you do in her, and you are golden, she should be attracted (as long as you do what I say below)
Be in an attractive frame from the beginning, being to friendly is going to kill you, always add a sexual innuendo, make sure it is congruent to you and the interaction. It will be weird if you act in-congruent.
Game like this is dangerous territory, remember, girls online are bored, don't take anything too serious until you see true investment.
Hard part will be getting from IG>Facebook, from there, solid text game will work wonders. You must keep the frame and escalate to higher frames.
Offer value, in that you know the school pretty well, and without sounding like a supplicating chode show her subtly that you are the man to go to on campus.
Here's a line to use incase she finds the situation weird or whatnot.
"Ya know, I've never done something like this, I thought it'd be weird, but you are a pretty cool open girl, I respect that."
Use this appropriately.