Being confused is OK.
In short: the difference in price isn’t big, so just go for 100W/20V cables and this means 5A. It’s your choice whether you need video or not. Video just costs more.
Tip: Buy the same colour cables for the same functionality. Otherwise you’ll be even more confused 
There are indeed already some other conversations that discuss USB-C cables.
Just search for “USB-C”.
Some of the cables I got as spare, see the following conversation: Recommendations for 2 meter USB-C - USB-C cable? - General Discussion - Philips Projection
Later I got some from Ali Express (Baseus and UGreen) and they work fine too.
I successfully tried charging, Samsung Galaxy S9, S10+, Dell XPS15, HP Omen15, Backshark 2, etc.