Well, looking at your interest list, it looks like you already have landscape covered with the 24-70. You could temporarily cover close up with the 24-70 by adding a set of extension tubes. Long term you will likely want something like the Z 105 micro, but that can probably wait until you see if you are willing to spend that much money. The extension tubes will set you back less than $50 US and yield good results. Here is a thread I started about my experience with extension tubes and the 24-70:
Extension Tubes I started with them and my 24-70 prior to getting the 105. The 105 micro lens would also make a great portrait lens, although the 24-70 will do for a while. That brings us to a telephoto for nature work. This is tricky as you can get a 3rd party for relatively cheap, the z 180-600 for a good bit more, or go crazy with a long prime at $6K and up. If I had to do it again, right now, I would go for the new 180-600. Having a native mount is preferred in my book, and it gets great reviews. There is a thread here about it, and several members own one.
Again, I wouldn't recommend the 50-250. It is a DX lens and will throttle your image to around 12 MP resolution.
A lot depends on your budget, and direction of your interest. Based on your stated preferences, I would think the Z105 micro at around $1000 US would be a good candidate. You will probably want to invest in a flash for macro as well. They can be had fairly inexpensively and are almost a must for macro work IMO.
The other route would be to get a set of extension tubes, and then pick up either something like a Sigma 150-600, which would require an FTZ adapter, or the Nikon Z 180-600 which would be my preference. This setup would give you landscape, closeup, nature and portrait. It would cost you more than the micro lens, but would give more flexibility. The down side is more money, and less capability in closeup and portrait work.
Be aware, this is my opinion based on my experience. I initially got interested in nature photography and bought the 200-500 and an FTZ adapter (the Z 180-600 was not released then). Still, it's a sharp lens and works well with the FTZ and I have had a lot of fun shooting images of mostly birds. I later got the bug for close up work and started out with extension tubes. They performed well, but I didn't like the short working distance. I also couldn't switch to taking pictures at any distance without removing the tubes. I discovered I was interested enough in macro to pick up the Nikon Z 105 micro. It never ceases to impress me with image quality. I also picked up a Godox 685 flash. I don't always use flash for closeup work, but I wouldn't want to be without it.
No need to apologize for asking questions. That's what the forum is for. Besides, we like helping other people spend their money.
