Looking at solo's from various songs and a lot of them include something like this

I am unsure as to how to play this, any help?
Is it really just plucking the G string and then the B string alternatively? Or am I meant to pluck both in one slowish strum or what? How does one go about doing this.

Just bend the G at the 12th then a quick hammer on then pull off from the 10th to the 13th and back to the 10th on the B string and repeat quickly.It's a common D Minor Pentatonic lick.
It depends on the song; the way you've written it indicates that only one note is sounding at once, in which case you'd play the bend on the G string then play the three notes on the B string and mute the note you played on the G string.
You're right, that is a super common line, so getting good at it will really pay dividends as variants of this kind of thing appear all over the place. The G and B strings are picked one at a time (at least how you've written it). I pick this kind of line with a quick D-U: I want my downstoke on the bend. Also, make sure you're putting a little wrist into the bends, as these sort of licks can be really tiring if you're using your fingers too much and not enough wrist.
Bends should be all wrist ideally, and make sure you play the notes for the correct amount of time. If all four notes have equal length don't fall into the trap of playing the legato notes faster than the picked ones.