Is the A7 IV worth it over the A7 III?

Yes for most buyers. The A7 IV adds a higher-resolution 33MP sensor, much better real-time tracking autofocus, a sharper EVF and improved video. The A7 III remains cheaper and lighter but trails clearly on autofocus and resolution.

Is the 28-70mm kit lens good enough?

It is a serviceable starter zoom with stabilization and a useful 28-70mm range. It is slow at F3.5-5.6 and not very sharp wide open, so most owners add a prime or a better zoom for low light and image quality.

How good is the autofocus for sports and wildlife?

Very good for the class. The 759-point phase-detect system with real-time tracking and 10 fps bursts handles moving subjects well. Very fast action and distant wildlife still benefit from a longer, faster lens.

Does it shoot 4K video?

Yes. It records 4K up to 60p in some modes, with microphone and headphone ports and a tilting screen. Long takes can trigger heat warnings, so plan cooling for extended recording.

Typically the A7 IV body, the FE 28-70mm F3.5-5.6 OSS lens, a battery, charger or USB cable depending on region, strap and body cap. Check the listing for the exact bundle.

Is it good for beginners?

It is capable but complex. The auto modes and tracking make it approachable, yet the menus and full-frame lens costs suit buyers who plan to learn. A cheaper APS-C body is easier to start with.