Since you're new, I would say buy a cheaper one (so the 61 key) since you're learning a relatively basic song.
After you've learned and progressed through, then you can upgrade to a more realistic 88 key one. It is unlikely you'll appreciate the difference until later on.
And who needs lessons when you have youtube!
http://www.youtube.com/watch?v=yh_wh-p0IKA
This is a nice and cheap one. Touch sensitive keys that will help you learn how hard/easy to press to get the appropriate sound so that when you play an actual piano, you won't look like a noob!
http://www.tomleemusic.ca/main/homek...127&inv=140385