The pentatonic scales (major or minor) are "safe" to solo with because the five notes in that scale all sound ok over any of the primary and secondary chords in the key. I.e. you can play any of the notes from the F#m scale over the chords of the song without worrying about a dissonant note. That said, remember that safe is usually boring so you want to get off the pentatonic and into some diatonic (full scale) or even chromatic (borrowing notes from outside the key completely). That takes a little more skill and experience (you're now using notes that can sound bad over some of the chords so you have to figure out what chord is being played and make sure you pick diatonic or chromatic notes that work with it). Still, it's worth doing. Probably 80% or more of the most memorable "hooks" owe their memorability to those notes outside the pentatonic.
John