I tried to learn piano when I was younger, as I think it is an amazing talent. The acoustic sounds that come from the hammer striking the strings when you press the keys is so beautiful!
I have always been interested in learning about how to play the piano.  What tips would you give a beginner to be successful at playing?
I think it's to really learn where to put your fingers and thumbs, on the right keys, so that when you play, you will play the right notes. 
Do you have to learn about music theory and chords?
I think it's important to know how the pressure you use can really effect the velocity of the key press, which produces the loudest notes.
What type of pressure are you referring to?  
The greater the touch of your fingers, produces the a greater force of the hammer hitting the strings, which will produce a stronger and louder note when you play.