Just got a new Mac book pro 2020.

Just got a new Mac book pro 2020. However im not sure how to correctly connect it. It came witha "C" on both ends of the line and also a square plug into socket adapter. I am not a computer savey person having my old Macbook Pro with the adapter line to the magnetic part on thr computer. Older computer

Now im not sure hoe i connect my new one. It came witha wire w a "C" on each end and a square adapter to attach it to thr plug. Im used to the lightening USB and am at a loss as to use the "C". im scared I"ll damage my new computer by doing something incorrectly. Help please! i"m 66 so not up with the newer connections. Thank you so much, Prue