What you are looking for is either a band pass filter to keep only frequencies within a certain range or use a combination of high and low pass filters to only keep the certain frequencies you are looking for. However, this will almost certainly not have the desired effect you are looking for. While the majority of human speech is within that range, there are still frequencies outside of that, if you restrict the frequencies to that range, you're going to end up with very muffled/muddy sounding speech which will likely be unclear and difficult to understand. This will also not eliminate background noise, any background noise within that frequency range will still be there.
When I deal with audio for my YouTube videos, the only equalisation I do to the audio is to apply a high pass filter to exclude frequencies below around 100Hz as this stops my voice from "booming" and improves clarity, I'd never cut out any higher frequencies as this will just decrease clarity and make everything sound worse. The solution to your problem doesn't lie in fixing the issue of background noise after the fact, it lies in the recording itself. Try and record in as quiet an environment as possible and use a decent quality microphone that is close to you. For my videos I use a lavalier microphone clipped to my shirt. A microphone built into a laptop or camera will usually be too far away from you and will therefore pick up a large amount of background noise. Keeping the microphone close to you will mean that it can pick up more of your voice in relation to the background noise.
Software such as Audacity do support noise reduction effects which will analyse a portion of the audio without speech and use this "noise profile" to remove it from the rest of the audio. This can work as a last resort in situations where an issue with the recording is only discovered after it has been recorded and there is no chance to re-record however it is no substitute for getting a good quality recording in the first place.
