Scales to Play Over Fm(add9)
Every chord is a subset of several scales: any scale that contains all of a chord's tones fits over it. Pick a chord to see the matching scales from its own root, the major keys the chord belongs to, and full fretboard diagrams for every scale on guitar.
A Fm(add9) chord contains the notes F – G – G# – C. Any scale that includes every one of those 4 tones fits over it — from the root F, that means F Natural Minor, F Melodic Minor, F Harmonic Minor, F Rock 'n' Roll, F Dorian, F Dorian Bebop and F Gypsy Minor. Start with the first scale listed: it is the most common choice, and the others color the same chord tones differently.
Fm(add9) is also diatonic to 2 major keys: D# major (relative minor Cm), G# major (relative minor Fm). In a song from one of those keys you can also solo with the key's own major scale or its relative minor pentatonic across the whole progression, not just this chord.