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.