yeah - its pretty simple

the notes are like the alphabet - A B C D E F G

and in between there are halfsteps - 1 fret is 1 halfstep

the halfsteps are

A A# B C C# D D# E F F# G G#

then it starts off on A again (notice between B and C and E and F there is no note for b-c and e-f IS one half step)

knowing that you can easily figure out the notes

example

you are on the d string - simply start counting from D onward.

and memorize a few basic shapes like octaves to quicky find the notes. if you are for example on the low E string7th fret you have an B - now you find that very same note one string higher and 5 frets lower - in that case the same B is on the a string 2nd fret.
pretty simple - the only exception it the b string - from g-string ot b-string the distance is only 4 frets.

octaves are two frets and two strings higher
or one string and 7 frets higher
or 3 strings higher and 3 frets lower
or 6 strings higher on the same position
(again the exception is the 1-fret difference of the b-string - and according to it the high e-string, which is 5 frets difference to the b-string)

so if you are on that B again you´ll find it
on the 9th fret D-string or
on the 14th fret A-string or
on the 4th fret G-string or
on the 7th fret high e-string

from fret 12 onward it starts all over again - so consider the 12th fret your zero-fret and start counting again.

just paint yourself a fretboard and write all the notes on it and you will see the shapes i just mentioned