I'm new to speedrunning this game and speedrunning in general (this is the second game that I've attempted to speedrun). This might be a really stupid question, but is there any difference between playing Wii VC Super Mario Bros. 3 on an actual Wii or using the backwards compatibility the Wii U has to play the Wii VC version on the Wii U? I transferred the data from my Wii onto the Wii U, so I would just like to know.

no but both vc's run at 59.689 FPS and the nes runs at 60.998 FPs

Also the category most friendly to beginers is any% and virtual console is banned

for any%

Thank you. May I ask why Virtual Console is banned for Any%?

The Virtual Console doesn't behave exactly the same as NES. There are some methods of doing the Wrong Warp used in any% that will crash on NES but not on Virtual Console.

Gotcha. I might just switch over to playing on an emulator, since it'll also be easier to practice if I do so.