How long after a girl becomes single should you wait before asking her out? Is this a good idea?

Ok, this girl I've been crazy about for months just became single recently. She really liked her boyfriend but he essentially got bored with her and just dumped her

I don't know how she's taking it right now (We haven't talked in like a month), but I have an idea. I have to call her for one of my teachers (taking a class she took, she left her stuff in it, teacher wants her to come get it). I was thinking of calling her tonight aobut it, and when she comes to get it, say that we need to like catch up (since its been months since we've hung out) and then ask her to like lunch or something. If we do that, I'd then ask her out on a date while we're out

It was just five days ago... Is this too soon? If so, what else can I do? Just be there for her? Tell her how I feel?

I sort of wanna tell her but I don't know if its a good idea. She means more to me than anyone else does. I care about her more than I do for anyone else, including most of my family. Just being around her puts me in a good mood and if I was having a bad day, hearing her voice was enough to cheer me up, she's made me happier than anyone else ever has

I've been with other girls and even when I was with them, I could admit that they were having a bad hair day or they didn't look great one day or something. Not her though... She's always been downright beautiful to me. She has an amazing personality and she's downright gorgeous.

She's the closest to heaven I've ever been and I'm pretty much constantly thinking of her all the time. I'd do anything for her to be happy and just seeing a smile on her face makes me happy...
How long after a girl becomes single should you wait before asking her out? Is this a good idea?
Post Opinion