Need help editing an MP3 file

I could really use some help editing an MP3 file. Nothing fancy. Just need to copy and paste a short snippet at the beginning of the song making the introduction of the song a little longer. I then need to simply delete a portion of the song to delete the instrumental portion of the song. Lastly, if possible, I would like to insert different lyrics at certain portions of the song. This is an important project and time is of the essence. If you can reach out to me I may be contacted at frosado8888@aol.com. Thank you.

I won’t attempt to give you step-by-step instructions but this should get you started.

There are a few ways of reducing or removing vocals but “traditionally” you don’t get good results. But Audacity has some new AI Plug-ins that may work better, or maybe some 3rd-party AI. (I haven’t tried these AI tools.)

Mixing is “easy”. So if you have a vocal-only track at the correct pitch and tempo you can mix it in. Or you can record your own vocal and mix it.

When joining clips, it’s usually best to use a crossfade for a smooth-unnoticeable splice. It can be a few milliseconds or a second or more, depending on what sounds good. And with music you should try to match the beats.