Well the first thing anyone wants to do is play their favourite songs, but I don't think just learning songs is the best way. I would learn some basic theory such as intervals and chords, proper fretting and plucking and holding the bass(including minimising injuries), learn the fretboard well, learn notation(not tabs). This way puts more meaning to the songs that you want to learn, and you can understand why a song is played the way it is.
Being able to transcribe is also a massive plus.