I always start with Grass; even in Gen VI, which was the first time where I was horrified by the final form of my precious Grass starter (Sceptile took time to grow on me, but that was more indifference). I mean, it was like Dr. Robotnik and Sonic had been merged and then given a green color scheme.
So unless Grookey ends up looking like a cross between Delphox amd Chesnaught, I’ll still be choosing the Grass-type starter my first playthrough, regardless of whatever ramdomizer tries to pair me with
I've always figured out my starter pokemon nearly at the beginning (which I believe besides kanto and alola were originally cyndaquil-torchic-piplup-snivy-fennekin but now I prefer cyndaquil-mudkip-chimchar-snivy-fennekin), except for alola and galar (because I liked primarina more than incineroar despite preferring litten, and I don't like the galar starters much)...I'm really hoping we get the evos very very soon so I can properly decide.
I've always been more of a fire starter person but Scorbunny just...doesn't catch me. Neither do the other two but at least I kinda like Sobble I guess.
Got Scorbunny from that screenshot thing, which isn't what I'm planning on going with although I have warmed up to it as a design upon seeing it move in-game and seeing it in the cute feature artworks they've put out.
I've always decided my first Starter from just looking at the base stage, and I've stuck with that. I get around to trying the others later in subsequent playthroughs.