Intro (Vocals)
E|---------------------------------------|
B|-7----5----8----7----5----8------------|
G|-7----7----7----7----7----7------------|
D|-7----7----7----7----7----7----x\------|
A|-5----5----5----5----5----5----x\------|
E|-------------------------------x\------|


  Riff A
E|------------------|
B|--3----2----3-----|
G|--2----2----0-----|
D|--0----2----0-----|
A|--0----0----------|
E|------------5-----|

Or power chords, if you prefer.
E|------------------|
B|------------------|
G|-7----------------|
D|-7----7----5------|
A|-5----7----5------|
E|------7----5------|


  Verse Part A (I remember the first time)
E|-----------------------------------|
B|-3-3-3-3-3-3-3----3-3-3-3-3-3-3----|
G|-2-2-2-2-2-2-2----0-0-0-0-0-0-0----|
D|-0-0-0-0-0-0-0----0-0-0-0-0-0-0----|
A|-0-0-0-0-0-0-0---------------------|
E|------------------5-5-5-5-5-5-5----|


  Verse Part B
E|-------------------------------------------|
B|-3-3-3-3-3-3-3--------3-3-3-3-3-3-3--------|
G|-2-2-2-2-2-2-2--------0-0-0-0-0-0-0--------|
D|-0-0-0-0-0-0-0--------0-0-0-0-0-0-0--------|
A|-0-0-0-0-0-0-0-----------------------4bp0--|
E|----------------4bp0--5-5-5-5-5-5-5--------|


  Prechorus (And if we could have)
E|----------------------|
B|-3----2----3----2-----|
G|-4----2----0----2-----|
D|-4----2----0----2-----|
A|-2----0---------0-----|
E|-----------5----------|


  Chorus (Cause we were young)
E|------------|
B|-3----3----|
G|-2----0----|
D|-0----0----|
A|-0---------|
E|------5----|


  Post Chorus (And we could last forever)
E|-----------|
B|-3----2----|
G|-4----2----|
D|-4----2----|
A|-2----0----|
E|-----------|


  Riff B (And there’s a chance for us tonight)
E|------------------------------------|
B|------------------------------------|
G|-4-4-4-4----------------------------|
D|-4-4-4-4-4-4-4-4-5-5-5-5-7-7-7-7----|
A|-2-2-2-2-4-4-4-4-5-5-5-5-7-7-7-7----|
E|---------4-4-4-4-5-5-5-5-7-7-7-7----|


  Build Up
E|----------------------------|
B|----------------------------|
G|----------------------------|
D|-7-7-7-7-7-7-7-7-7-7-7-7----|
A|-7-7-7-7-7-7-7-7-7-7-7-7----|
E|-7-7-7-7-7-7-7-7-7-7-7-7----|


  Ending (And we could last forever)
E|-----------|
B|-3----2----|
G|-4----2----|
D|-4----2----|
A|-2----0----|
E|-----------|


Song Order:
Intro
Riff A x2
Verse Part A x2
Verse Part B 
Verse Part A
Riff A x2
Prechorus 
Chorus x4
Post Chorus
Riff A x2
Verse Part B
Verse Part A 
Verse Part B
Verse Part A
Riff A x2
Prechorus
Chorus x4
Riff B x2
Build up
Chorus x8
Ending


Legend:
x\ - pick slide
b  - bend
p  - pull off