I've been binge watching a lot of speedrunning videos over the past month or so and I've decided to give it a shot at this game, the only problem is, I'm unsure and unaware of how to get an emulator working. So any help and recommendations would be highly appreciated, thanks!

EDIT: I've heard OBS is a good way to record your screen. Is OBS the best program to use?

OBS is one of the best software to stream and record stuffs currently. Download BizHawk, download a rom, drag&drop the rom on BizHawk and owo, it works.

This issue is not directly related to SMB1 speedrunning, and this serves as a better place for finding the answers you need: https://www.speedrun.com/Streaming/forum