Buying a Camera (Nikon)

Hi, i need some advices maybe some of u are a photographer or passionate about picture.
I would like buy a Nikon Z6, i find some cheap one with a Lens 24-70mm f/4 ( i want something like that) but i don’t know if f/4 is good or not ? iam a beginner and my goal is to take peoples and wedding but also somethime landscape for sure, 24-70mm for learn and after i will see, but is better to take a F/2 because F/4 is more for landscape no ?