Learn music theory for beginners with these free videos and learn some basic music theory for beginners. You'll understand what you're playing if you have a good foundation in music theory.
These tutorials will help you in music improvisation and composing as well -
www.zebrakeys.com/lessons/beginner/musictheory/
You'll learn about the Music Intervals (whole tone and semi-tone) and will help you to understand better when you start to learn how to construct Major Scale and learn about to construct them.
Learn how to play all the Major Scales in all of the 12 keys.
The Intro to the Circle of Fifth diagram will give you an overview of how many sharps (#) and flats (b) are there in a particular Major Scale.
There are 12 Keys in music, and you'll learn all the 12 Key Signatures and how to read them (this will also noted in the Circle of the Fifth Diagram.