Learning the fretboard is easy if you learn it in these three steps:
Memorize a few reference points on the low E and A string. They fall on the exact same frets!
Memorize six octave shapes (one for each string).
Apply the octave shapes to each reference point and extend the octaves up and down the neck.
Let’s see that on the fretboard:

If you follow these steps with one reference point per day, it would take a week to practice all the reference points. At the end of the week, the fretboard would be memorized. Practice each note for ten minutes. Start at the low E string on the first pass through. Start on a different octave on each pass so that you learn the fretboard more completely. There are electric guitar lessons here. Here’s a great video that describes the process: