Know I've probably written too much already but ref getting to know the notes on the guitar, the fret markets at the 3 5 7 9 and 12 frets are -as Soulman points out-the best way to navigate the fretboard. Also learning to tune by "relative" tuning rather than just relying on an electronic tuner will help you remember.

As you know, the standard tuning bottom bass to top treble is EADGBE. The note on fifth fret of bottom E string is same as open fifth string (A).The note on fifth fret of fifth string is same as open fourth string (D). Note on fifth fret if fourth string is same as open third string (G). The odd one out is the fourth, not fifth, fret of third string is same note as open second string ( and then fifth fret of second string is same as open top string (E).

Tbh, whilst I always know the chords I'm playing I don't really consciously think about names of notes I'm playing on guitar whereas I'm constantly worrying about it when I'm playing keyboard. Maybe I'm just finding it more difficult learning keyboard because I'm now having to learn to read music more and understand more theory-or it could be that I'm just getting old😞