I'm having difficulty identifying and playing the sharps which are C# , D# , F# and G# . Do the sharps apply to all the bars ?
Yes they do because they are the key signature of a piece. The key signature tells you what key you are in and what notes to expect. Since you are in the key of E major, you will most likely use the notes E, F#, G#, A, B, C#, D# which the four sharps represent. Those are the notes you should use unless a different accidental is applied to a note.
The #### circled in red in your answer are the key signature. YOu can read this as "four sharps", that stand for E Major (or C# minor). Basically all F C G D in the score are sharp, no matter in which octave. The simplest case is No Sharps/No flats (C Major / A Minor), in that case all notes are natural.
You can find a list of Major Scales in any basic music theory book . Also look on the web for a list of scales .Each scale has a note name.That is the keynote of the scale. A short trick to help you with sharp keys is to look at the last sharp symbol .In the diagram above the four sharps are shown in a red circle. The last sharp is on the D. So go up one position and you will be on the keynote which is E. On any sharp key take the last sharp and go up one position for the keynote.
So what do you do with that? Just play a major scale starting on that keynote and practise that a few times before you play the music .Use it as a reminder. It
s there to help you and not to confuse you .
There is an opposite trick for flat keys . Pick the next to last flat. That is your keynote .
Dont worry about Minor Keys yet as any extra sharps or flats will be written in the bar when they are needed.
But All the Bars are affected by the Key Signature .
The rules about Keys are there to help you .