At this point you should know the names of the strings. From the ceiling to the floor:
It is important to add music theory and knowledge of the guitar along the way of developing guitar skills. To start, memorize the following:
A whole step is the distance between two frets which is essentially skipping a fret. For example going from the 1st fret to the 3rd fret is a whole step.
A half step is the distance of one fret or simply moving to the next fret. For example moving from the 1st fret to the 2nd fret is a half step. In the musical alphabet, going from notes B to C and E to F are considered half steps.
The musical alphabet consists of:
A B C D E F G A B C D E F G
After G the alphabet reverts back to A and vice versa. Within the musical alphabet there are whole steps (w) and half steps (½) steps which would look like this:
A w B ½ C w D w E ½ F w G w A