scales and notes on fretboard

what im not getting is how the scales are placed on the fretboard if they run out of room on the 1st string (are they just wrapped around to the 6th string?) and where a scale can start, like, a major scale can start on open 5th string , 5th string 5th fret, d string 7th fret etc.etc.

If you start on a note and count 5 frets back (or 7 frets forward) and one string up (in pitch... physical movement is down), you will get the same note.

The previous statement is the rule for crossing all strings, except from the G to B. Since the B string is tuned at the fourth fret, the rule changes to 4 frets back (or 8 frets forward) and 1 string up when moving from the G to B string.

Instead of looking at it as staying at the same fret level and going across the fret board, look at it as going up and down the fret board with patterns. The way I approach that is I look at the scale pattern for the same key, that has the root on the bass E string and look at the same scale with the pattern that starts on the A/5th string. once you have those patterns down, you can connect them. I hope this helps.