How to read tablature? 
Intro - strum or fingerpick, x2 -:

    Db             Bbm            Gb               Ab 
xA|-------3-----|-------0-----|-------0----0~-|-2-----|
xE|----0-----0--|----0-----0--|----1------1---|---3---|
xC|-0---------0-|-0---------0-|---------------|-----2-|
xG|-------------|-------------|-2-------------|-------|

Verse:
Db               Bbm                 Gb 
I remember your bare feet down the hallway
  Ab                    Db 
I remember your little laugh
                 Bbm 
Race cars on the kitchen floor
        Gb            Ab                         Db   - Intro part - Bbm  Gb  Ab 
Plastic dinosaurs, I love you to the moon and back

Verse
Db               Bbm                Gb                 Ab                  Db 
I remember your blue eyes looking into mine like we had our own secret club
               Bbm             Gb             Ab                       Db 
I remember you dancing before bed time then jumping on me waking me up
                     Bbm 
I can still feel you hold my hand
Gb           Ab                       Db 
Little man, from even that moment I knew
                           Bbm 
You fought it hard like an army guy
  Gb                      Ab 
Remember I leaned in and whispered to you

Chorus:
Gb                  Ab 
Come on baby with me
                    Db      Gb 
We're gonna fly away from here
    Gb       Ab          Db     Bbm  Gb  Ab 
You were my best four years

Verse:
Db              Bbm                  Gb 
I remember the drive home when the blind hope
          Ab                      Db 
Turned to crying and screaming, "Why?"
                        Bbm 
Flowers piled up in the worst way
             Gb                   Ab 
No one knows what to say about a beautiful boy who died

Verse:
Db                    Bbm 
And it's about to be Halloween
             Gb            Ab                        Db 
You could be anything you wanted if you were still here
               Bbm              Gb 
I remember the last day when I kissed your face
  Ab 
I whispered in your ear

Chorus:
Gb                  Ab 
Come on baby with me
                    Db      Gb 
We're gonna fly away from here
Gb                      Ab                          Db 
 Out of this curtained room in this hospital grey
                 Gb 
We'll just disappear
                  Ab 
Come on baby with me
                   Db       Gb 
We're gonna fly away from here
    Gb       Ab         Db 
You were my best four years

- Intro part -

Bridge:
            Gb                Ab                Db 
What if I'm standing in your closet trying to talk to you?
          Gb                Ab                    Db 
What if I kept the hand me downs you won't grow into?
              Gb                   Ab             Db 
And what if I really thought some miracle would see us through?
                Gb           Ab                Gb           Ab - once -
But what if the miracle was even getting one moment with you

Chorus:
- Gb -               Ab 
Come on baby with me
                   Db       Gb 
We're gonna fly away from here
                  Ab 
Come on baby with me
                   Db       Gb 
We're gonna fly away from here
    Gb       Ab         Db 
You were my best four years

Outro:
Db               Bbm                 Gb 
I remember your bare feet down the hallway
  Ab                        Db 
I love you to the moon and back