To give you a quick solution:
First, in the piano roll of the instrument you wish to enter the score into, look right above where the keys end. See the two pics of different sized keys along with the 'abc'? Select the 'abc' to switch over to lettered notes.
Next, bring up the tab you wish to translate. Look at the string, take for example an 'E', then count the semitones to the actual note. A 0, or an open is just the 'E', but a 1 represents one fret above the note, or an 'F', a 2 represends an 'F#' and so on.
To achieve the right tempo, I would suggest placing the origional track's MP3 into FL studio as an 'Audio Clip' and then right clicking the image of the waveform in the Audio Clip plugin screen and selecting 'Detect tempo'
That's my advice.