My vision nearly blacked out earlier, could this mean my blood pressure is too low or blood sugar is low?

Yes, just so: You experienced an "orthostatic" episode, where your blood pressure temporarily became too low. If this happens all the time and results in passing out, you may need to see a cardiologist for this. If it's just a time to time annoyance, that's almost normal, and nothing anybody would treat, except to advise you to stay hydrated and get up more slowly.