Hey who do I talk to about the rules for this run like when I start the timer, when do I stop the timer, etc? I already have the route done and tested but need to see when I start the timer

Well, generally you'd talk to someone who has already run it, like a moderator, or watch a run of it already completed. I think I've seen about 3 places to start a timer. "SDA timing" starts when you gain control of your character. "ZSR timing" starts when you press the last button on the main menu. The other way is starting it when you reset the game (seen it used for Persona 4 and I've used it for McPixel). There's possibly more I don't know of. Different games have different ways of doing it (i.e. Deus Ex HR starts after the story-driven cutscene at the start that wastes several minutes).

I haven't been able to find any runs of Custom Robo N64 on nico or google (though I did find some of V2), so I guess you can just pick something reasonable. My suggestion would be to start the timer after confirming your name entry and stop it at the last input before the credits start.

I can add whatever timing you decide on to the rules if you want.