The numbers 4 /4 at the beginning are the 'Time Signature' showing that there are 4 beats in each bar.
The notes with the long vertical line beneath them, are Quarter Notes, or Crotchets, and last for ONE beat, or count. The shorter vertical line, represents a Half Note, or Minim, and lasts for TWO beats.
The long vertical line with a dot next to it, is a Dotted Quarter Note, and is worth One and a Half Beats.
The long vertical line with a short horizontal line on the bottom, is an Eighth Note, or Quaver, and is HALF a beat long, while the last note of the piece, has no markings at all, and is a Whole Note, or Semibreve, and is worth FOUR beats.
If you get it all right, you will see that the music above, is the beginning of Jingle Bells!
These are just a few of the symbols used in Guitar Pro, but I think you will agree, that it is much easier to read