New,and want to combine 2 tracks together

I’m an absolute newbie to music editing and Audacity, and am using the portable version of it.
I’m running it on Windows 7

I want to combine two tracks, in this case, Taylor Swift’s Bad Blood. There’s one featuring Kendrick Lamar, and the other one with just Taylor Swift.

They’re noticeably different other than just the voices. The one with just Taylor Swift starts a little later, and is slightly quieter.

How would I delete some of the starting parts, and combine it into one? Also, if I also want to combine an instrumental version, will it be the same?

Sorry but Audacity Portable is not our project. Here is your support address:

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