Landing in Espana! (Madrid)

Half Egyptian/ Half Romanian will be landing in beautiful Madrid in the 20th of August.

I LOVE adventure, this is why I just booked the tickets without thinking of ....

1- Where to stay? And how much that would cost me? The cheapest nice place OR the nicest cheap place if you know what I mean :))
2- Where I 'must' visit? And other places I shouldn't go.
3- How and where I can enjoy the night life?
4- Who would be interested in hanging out with me? (I am a very friendly and easy going guy).

I am planning to spend a whole month in SPAIN in general since I am learning Spanish and I would like to practice it in the source.

How would you recommend to spend the 30 days there? How many days in Madrid, other cities etc etc.

I will highly appreciate your help :))