Since you happen to mention you are also interested in astronomy and your signature says you have a 90mm f/11 telescope (I'm guessing it's a refractor) it's fairly easy to connect the camera to the telescope so that the telescope becomes the lens.
Assuming you're telescope uses 1.25" diameter eyepieces (the most common) then you'd need one of these:
Amazon.com Celestron 93625 Universal 1.25-inch Camera T-Adapter Telescope Photo Adapters Camera Photo
That inserts just like an eyepiece and the back of it has industry standard "T-threads". Next you need to adapt the universal t-threads to the Nikon-specific camera mount. To do that, you would need a "T-adapter" (they make these for Nikon, Canon, Sony, etc. etc.). This "T-Adapter" has female t-threads on the front side, but has camera-specific mount on the back.
Amazon.com Celestron 93402 T-Ring for Nikon Camera Attachment Celestron Adapter Camera Photo
Screw the T-adapter onto the T-mount, then attach to your camera as if it were a lens. You can now insert the camera into the telescope's focuser (just like a telescope eyepiece) and the entire telescope is now a "lens" for the camera. (BTW, you should attach it straight-through to the telescope... don't use the 90º diagonal).
Depending on how much travel your focuser offers, you MIGHT need an extension. The 90º diagonal typically takes up about 2" worth of focal length and your telescope camera sensor may be too close if the focuser does allow enough travel. The 2" extension is cheap (it's just a hollow metal barrel.) Try using the camera without the extension (because the fewer components between the telescope and camera, the more "rigid" it will be -- so avoid unnecessary extra components whenever you can.) If you find that the image is not focused and, as you move the focus travel back you notice the image is only starting to come to focus before you run into the limit of focus travel... then add in a 2" extension to solve the problem. Here's a link to an extension:
Amazon.com Orion 5123 1.25-Inch Telescope Eyepiece Extension Tube Camera Lens Extension Tubes Camera Photo
An image of the moon is an easy shot at f/11. Just set the shutter speed to the inverse of the ISO setting (e.g. at ISO 200 you would use 1/200th. At ISO 400 you would use 1/400th, etc.) No tracking motors, etc. are needed for the moon because it's bright and you can use a very fast exposure. The moon usually looks best when imaged somewhere around 1st quarter since the sun is lighting it from the side (from our perspective) so we see nice deep shadows and that really helps the craters appear "3D". If the moon is "full" then the sun is "at our back" lighting the moon from straight-on -- we don't see any shadows so everything looks "flat" or "2D". 3rd quarter is also fair game, but we don't see the moon after sunset when it's 3rd quarter... you have to wake up a few hours before sunrise to get those images.
Planets are somewhat similar (some tracking helps, but it doesn't need to be precise). Planets are usually handled by shooting a minute's worth of video and then using stacking software (such as "Registax", etc. which happens to be free) to build the stacked image of the planet (there are numerous YouTube videos that show you how to do this.)
Deep-space objects (Galaxies, Nebulae, etc.) are much more difficult... they DO require many long-exposure images and that means you need a telescope that can track precisely and you usually also need an "auto-guider". This is where astro-imaging starts to get very expensive. My first low-cost mount couldn't handle it. I bought a more expensive (allegedly better) mount ... also not able to do the job. I finally gave up trying to be cheap and bought a $3k mount (by the time I was done with accessories it was closer to $4k) and that DOES do the job fabulously. Probably the "lowest" end mount for very basic astro-imaging would be something like a Celestron Advanced VX mount (about $700-800 I think, but I'm not checking prices) but that's low-end... a better mount would be around $1500+ if you want to get serious.
You'll need to look through the viewfinder to focus. Until the Nikon D810a (a camera specifically designed for astro-imaging) previous models don't have "exposure simulation" when using the live-view screen. That means the camera tries to increase the exposure vied in "live view" (due to all the blackness of space in your image) and that causes anything non-black to be totally blown out and everything is just a big white blob with no ability to tell if you are focused or not. Some image-acquisition apps such as "Backyard NIK" can get around this -- but that would involve taking a laptop out with you to the telescope so you can connect the software to the camera.
Anyway, the moon is a very easy astro-image and doesn't require any expensive equipment, tracking, advanced software, stacking, etc. to get lunar photos. You should definitely try it.
Planets are only slightly harder because they use video capture and then use "stacking" software.
Imaging deep space objects (galaxies, nebulae, etc.) is hard... and the equipment that does it well tends to be costly. Save that for later.