Which bike should I get for my first bike?

In terms of weight, the Giant may be lighter and comes with a 2×11 groupset; I would check the drivetrain wear and the condition of the bearings.The other bike doesn’t specify whether the groupset is 2×11 or 2×12, but this can be checked. Regarding components, it has Dura-Ace, which is a plus. And it also applies to checking the transmission for wear even if it indicates that it is new; both are good options.But you must evaluate what type of routes you want to use it for; each one has a different geometry.