My advise is to learn the fret board. If someone says a root note, or a chord name; then you need to know where the root of that chord is on your bass. you can do this with scales and warm up exercises and such..
Study up on some theory. Major/Miner scales. Pentatonic Maj/Min.
Study the Circle of Fifths(Fourths).
Study the simple Chords Major chords, Minor Chords to start. Then work up to 7th chords and on to augmented diminished and such is more advanced.. but start with the Maj/Miner Chord tones and the Pentatonic Maj/Min (It has all you really need right now).
The interval qualites is what you are looking to get ingrained into your bass-being..
(Honestly a little keyboard will help you with this. if you have apple products Garage Band is a great little app. its like a tiny studio in your pocket! or tablet!)
Learn to play songs you like. It will keep things fresh and fun (I mean we 'play' music after all right?

) This alone has kept me going after all these years.
Eventually you get the guts to play out somewhere, even if its in front of neighbors in your garage. find some jam mates. and maybe get into a band. the sky is the limit.
there is tons more, but soak this up for now, and post back when this sparks more questions.