I've been trying to build up my right hand speed, but every learning resource is giving me conflicting information. Always rake, never rake, always start with first finger, always start with second finger. Which is the correct way to practice for the purposes of increasing speed and accuracy?
unfortunately there's no "right" way as there is with, say, pick technique. as long as it's comfortable, everything is valid, and you're somewhat responsible to learn how to play with and without raking, being able to use static and floating thumb technique when necessary, palm muting, thumb picking, using 3-4 fingers...if you can do it with your hand, there's gonna be a situation where it's valid to use that technique on your bass guitar.

personally, i always start with my second finger, but i also typically borrow clawhand banjo technique, so that feels most conducive to that approach. just experiment and learn every piece of music you want to learn in as many ways as possible and figure out what sounds and feels best in what situations.
modes are a social construct
Tap out paradiddle, everywhere, all the time - driving, watching tv, etc. If your right hand is free, tap out paradiddle. I also tap out drumbeats. I'll make my index the bass drum, middle the snare, and use them both for toms/rolls. Been doing this for almost 30 years. Because of this, I don't have to start or end with any particular finger. If need be, I can double or even triple pluck with either finger. I can use them independently.

♫Just keep tapping. Just keep tapping. Just keep....♫
"Quick to judge. Quick to anger. Slow to understand. Ignorance and prejudice and fear walk hand-in-hand."
- Rush, "Witch Hunt"
Because I play upright as well as electric, I tend to lead with my pointer and rotate between that and the middle. Its what works for you in the end.
It is only because of the Classical pizzicato training of the Bass Violin that anyone would write that one should start any form of plucking sequence with the Pointer Finger.

This is due to the holding of the Bow, whether Violin, Viola, Cello, or Bass, the Pointer finger is sacrificed from the grip of the Boa and freed to be employed for the purposes of the pizzicato effect.

From that case, teaching a walking bass line, the traditionalists will teach the student from where he already is experienced, that would be Pointer Finger.

We are so far beyond that now, and even beyond Leo Fender placing a finger grip beneath the G String for the Bass to be strummed with the thumb like some guitar and ukulele players (come on Leo! what Bass Violin Player did not ever tug towards the low end?), that all bets are pretty much off.

It was not until college that I was ever around another bassist, and came into lab one day and the other bassist, who was I suppose allegedly so far ahead of me, was playing a part that was practically a walking bass line with on finger.

I asked about that, and he said for consistency of notes. For that purpose, due to length and muscle mass difference between the two fingers, I learned something as I accepted his explanation.

I googled that guys name, and cannot find anything about him and what he has done with his career, unlike the drummer he got to play with there in the Music School, Sonny Emery.

So, I am with the rest of the responders, alternate the fingers on the walk. If you are doing that one thing, you are doing it right.
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Learn Iron Maiden songs. Triplets taught me how to play fast. Once you can get to something like real-time on a song like "the trooper", it's just one small step to turn the quick triplet into quick runs. Also, +1 to tapping.