This is a godd little bass line it's easy and is good when played with a few variations

Tuning: Standard (G,D,A,E)

G -----------------I
D -----------0-0-2-I
A ------2-0-2-2----I
E -0-0-3-----------I

G -------------------I
D -------------------I
A ------2-0-0-0-12/0-I
E -0-0-3-------------I

G -----------------I
D -----------0-0-2-I
A ------2-0-2-2----I
E -0-0-3-----------I

You can keep repeating and switching then around a bit to find the way that suits you best.