What lens is better overall nikon 14-24mm or 24-70mm both 2.8?

I'm just looking for a lens to have fun with and don't know which one is better for pretty much just fun

That is some expensive fun. If it is a lens to use most of the time, the 24-70mm is more useful.

They are really for two different purposes.

The 14-24 is an extreme wide angle lens, and while traditionally used by most people for landscapes and wide views, some fun can be had by using the lens up close.

The 24-70 is more or less considered a "normal" lens, which approximates what you see in normal life. As such, it is probably going to be the most used - and therefore the most useful lens.

These are full frame lenses, and most photographers buy the 24-70 first, then the 14-24.

Better for what exactly?
If you want to take more wide angle shots then the 14-24 mm would be best.
If you want to get a bit closer to images then the 24-70mm would obviously be better for you.
It all depends on what YOU want to do with an extra lens.

A lens "to have fun with". My mind boggles at the thought of the "fun" you can have with a lens!

I have a 10-20mm - at the 10 end you can get some real funny portriaits that my grandkids love. Looking down on them they have tiny feet and big round faces - like a Cheshire cat.

First things first - is your DSLR 'full frame (expensive) ir 'crop frame' (basic to medium)? If it is crop frame then to some extent both of those lenses are overkill, suitable for the greater demands of full-frame. You could spend your money to better effect on a lens for crop-frame.

For true 'fun' you might want the widest possible lens, thus think of 10mm starting on crop frame. There's a good Tamron at 11 to 17mm f2.8 constant for crop frame, not too expensive, though if you are thinking of the 14 to 24 clearly money is not a problem to you! Indeed the 14 to 24 would be the more 'fun' lens on full-frame.

Go to a good retailer and see the effect of lenses around those focal lengths - you don't need to see the actual f2.8 lenses to get an idea of what those numbers do for the image.

Overall? The 14-24mm is a wide to normal/standard zoom lens which is good for landscapes, group shots and shooting people in general. The 24-70mm is a normal/standard to short telephoto lens which is good for shooting people, portraits and close-up portraits. They vary somewhat in use so it really is difficult to tell which is better than the other unless we know exactly what situation you need the new lens for. Fun is just to broad.

I personally would opt for the 24-70mm. On the 24 end you can capture wide angle shots as well as normal at 55mm. But the 70 mm makes an ideal portrait lens (= a 135mm in 35mm terms). I don't think the larger size would bother me, but I'm a guy, and don't know your preferences as to amount of weight you want to carry.

This is a bit like asking "Which is better, a shirt or a pair of trousers?" They both cover bits of the body but different bits. It's the same with those lenses. There's no "better" because they cover different focal ranges. The 24-70mm can't take really wide angle shots but the 14-24mm won't be much cop for taking portraits. It's horses for courses. Pick the right lens for the job you want to do.