Real Madrid - Barcelona Match - Help Please

Hi,

First of all I want to tell I like all kinds of sports and football is one of the most favourite sport for me. For this reason I want to make trip for this weekend.
This weekend two big matches will be played.

Friday GMT 19:45 -> Napoli - Juventus
Saturday GMT 15:00 -> Real Madrid - Barcelona.

Second leg of my trip is, Real Madrid - Barcelona Match. So I have some questions for you :)

1-) Where can I buy the match ticket? I found a website where the lowest price is Protected content . Is this price normal? Can I found ticket in the matchday?

2-) Any hotel advice(parameters: hotel, airport, downtown and may be not so expensive:))?

Really thanks for suggestions.