This is a serious switcher issue all the time. On the PC, the Home key moves to the start of a line. On a Mac, it moves to the start of a document. On a PC, the End key moves to the end of a line. On a Mac, it moves to the end of a document.
The Mac equivalent of PC Home is CMD-LeftArrow.
The Mac equivalent of PC End is CMD-RightArrow.
There are exceptions of course. If you use Microsoft Office on your Mac, you can set its preferences to do the "PC thing" with the Home and End keys. Many web sites, including this one, do the "PC thing" with Home and End when you are typing text in a text entry box like the one I am using to enter this response.