This material will help you how to play intervals on guitar so that study this material well. Red letters show you the root note, blue ones are basic intervals and black ones are flats and sharps. I did not want to get into details about naming (like perfect, augmented, diminished). If you have read the intervals lessons in the Theory section I know you are able to find names of intervals easily.
Play these intervals in two ways - one note at a time (melodically) and two notes at the same time (harmonically.) Please try to see the practical patterns on the fretboard and maybe you can study on just one string and then using all the other strings. It will sure help your learning.