How to ask out a girl without looking like a fool?Watch
Don’t move too quickly talk to her and be friends for a bit first. From experience asking a girl you barley ever talk to out doesn’t work. You need to speak to her so she can get to know you and then ask her out
I like this girl a lot and she is in my uni. I have never met her but I have seen her a lot of times and recently she added me on Facebook nearly a year after I sent her the request. How should I approach for a date?
Unless she's shown you a lot of interest since accepting your request (e.g. starting online chats with you, Commenting on or 'liking'; a lot of your posts etc. I don't see this going anywhere.
If you cannot answer yes to any of those questions, then you'll need to work the foundations as Krombopullsvoid mentioned. Based on what you've written, chances are she'll say "no" if you just try and ask her