1 Learn to mute that beast. esp if you play 5 or 6 string Bass.
2. Rhythm should be a focus. Learn some different rhythms. and learn to lock in up to 16th note patterns; Whole note, Half note, Quarter/8th/16th note patterns are a good chunk what you will be playing for Rock and Metal, however in any genre you will find has their own nuances for rhythmic interpretations. a good metronome, or drum machine will help you get locked in on some basics. Victor Wooten said it quite eloquently, "I am in the Rhythm section, not the Notes section". take heed.
3. Learn with Fingers and with a Pick. if you play metal look on Youtube for inspiration for 2-3-4 finger techniques for speed. obv a pick will be fast, but takes a different skill approach and has a cutting tone, or attack if you will, and consistency are plusses. I find that fingers cant quite duplicate, but can come VERY close with good technique and some nail for 'bite' that a pick can do. muting technique is a bit different for the plectrum, but for speed and stamina I recommended at least trying one.
4. Dynamics! I crank my volume on my bass and use my hands to control the amount of attack intensity I need, or the amount of 'quiet' that comes through, muting and dampening will help you achieve a sense of dynamic range too IMO. sometimes its 'How you Say it' just like when you tell a story, you use inflection, vocal dynamics and pace to get your point across. same for music.
5. Learn the fret board. Learning the Diatonic Major and Minor scales in every key (learn how to apply them later) also the Major and Minor Pentatonic, and the Blues scale, again in every key. Chord Harmony and Modes will be a byproduct of this later down the line, but knowing the fret board is invaluable.
6. Train your ear. a keyboard may help in this regard. Interval and Chord qualities should be studied aurally. Playing and listening to a lot of music is the way. It will be a long journey, but a rewarding one.
Jury is out on if you need to learn to read music. If you plan to be a professional then it is necessary IMO and will get you gigs you may not otherwise get. If you are just in it for fun (like me) I get by on the above way more than I do reading notes. A grasp on that list of 6 things has kept music fun for the past two decades for me. If you can find the fun in 'playing music' then it can be a lasting event in your life.
Good luck