I like this song and couldnt find a bass tab for it so i decided to tab it myself! Have fun!
Intro and Verse
G---------------------------------|
D---------------------------------|
A-1-1-1-1-1-4-6-4-1-1-1-1-1-4-6-4-|
E---------------------------------|
Pre-Chorus
G----------------------------------|
D----------------------------------|
A-1111111111111111-3333333333333333
E----------------------------------
Chorus
G---------------------------------------|
D---------------------------------------|
A-11111111-44444444----------11111111---| X2
E------------------333333333------------|
[ Tab from: https://www.guitartabs.cc/tabs/a/ashlee_simpson/lala_btab.html ]
In the second verse there is a pause u play the one part and pause then start over again.
Verse
G---------------------------------|
D---------------------------------|
A-1-1-1-1-1-4-6-4-1-1-1-1-1-4-6-4-|
E---------------------------------|
Pre-Chorus
G----------------------------------|
D----------------------------------|
A-1111111111111111-3333333333333333
E----------------------------------
Chorus
G---------------------------------------|
D---------------------------------------|
A-11111111-44444444----------11111111---| X4
E------------------333333333------------|
During Bridge play chorus
Intro
G---------------------------------|
D---------------------------------|
A-1-1-1-1-1-4-6-4-1-1-1-1-1-4-6-4-|
E---------------------------------|
Chorus
G---------------------------------------|
D---------------------------------------|
A-11111111-44444444----------11111111---| X4
E------------------333333333------------|
Bridge: Again play chorus here.