I want to get into speedrunning smb but I do not have an nes, any help would be appreciated

The most reccomended emus are: Bizhawk, fceux and nestopia. I've heard of openemu or something like that but I've never used that.

Thanks for the help, I'm trying out fceux, I'll try those other two you mentioned as well.

I recommend Nestopia as it has way less input lag then the other emulators listed. I've been getting some of my irl friends into speedrunning and I've recommended Nestopia to all 3 of them.

Nestopia has lower input lag than FCEUX. I used to use FCEUX then immediately when I played on nestopia I was orders of magnitude more consistent from the lower input lag. I think it's only 3 frames or so.

OpenEmu is a Mac emulator and can run either the FCEUX or Nestopia core, but at 60fps instead of the NES framerate of 60.0988139fps.

I highly recommend OpenEmu if you can only play on a Mac.

Really? I am playing SMB on a decent laptop, with Skype and File explorer open in the BG, and notice NO lag with FCEUX.

"notice NO lag with FCEUX."

notice is the key word there - you definitely have input lag

When you are just learning the game, it doesn't matter nearly as much, since the tricks you're doing won't be as precise - but once you're incorporating things like pipe jumps, it will start to matter a lot more that some number of milliseconds pass between pressing a button on a keyboard and mario responding. Your brain will adapt, but it's still more difficult to account for the timelapse than it would be playing on an actual console with a CRT monitor, where the input lag is effectively zero.

so optimizing an emulator to minimize input lag is a worthwhile thing to do, because even if you played emu on a literal supercomputer with no other programs running, you'd still have significantly more lag than a NES using a CRT

Also the word "INPUT LAG" is different than "LAG" how you would normally use the word. Input lag is just the response time between pressing the button and mario responding. The game could run smooth as butter and still have significant INPUT LAG.

Although clearly it's possible to be top-tier on an emulator with some level of input lag. @Tecate is a prime example of a person with a 4:56 that uses emulator, and always has used emulator - and can still reliably execute ultra-precise multiple-frame-perfect tricks like 1-1 FPG