Could somebody help me download a third party library for c?

I'm in the process of learning the c programming language, and I would like to transfer data from columns in excel to arrays in c. I have came across the third party libxls library, but I'm hesitant to download it because I ultimately don't know what I'm doing. What do I need to do? please be as specific and detailed as you can.

Also, if anybody know of an objectively better way to transfer data from columns in excel to arrays in c (i.e. fewer steps, or safer), please explain that to me.

thanks you.