Short and Long notes
It may sound boring at the beginning but this is how your bass line comes to life and how you can make it feel good.
Short notes are played staccato and shown with a dot underneath the note. You are shortening the note duration by plucking with your 1st finger and resting the 2nd finger quickly on the same string (acting as mute) and vice versa. The notes with a line underneath are played as normal.
Improve how you control a note and your feel will improve.