Astrophotography can easily become a gear-driven hobby if you let it, but it doesn't have to get out of control to take amazing pictures. There are, however, a few basic items that will get you started. Not all of these are strictly necessary to take great night photos, but these are the basic items that will help you go from "interested" to "active" in astrophotography.
1. Intervalometer
Some modern cameras have these built-in, but most cameras will limit your exposure length to 30 seconds. An intervalometer allows you to set your own exposure length and set the intervals between each exposure to ensure that the sensor stays cool while shooting. It will also allow you to remotely trigger the camera, so you won't cause camera shake while pressing the shutter release button yourself. Find out more here.
2. A sturdy Tripod
This one is a must. You really cannot take good night photography without a tripod. You don't have to go for the most expensive tripods on the market, but you really don't want to go for the cheapest here either. This is one of those tools where a solid investment early will lead to great results later on. As you add on more gear down the road, like a tracking motor or a guide scope, you want a tripod that can hold the weight without shaking under the weight. You also want a tripod that will hold steady in a light breeze. It's all about stability here. I recommend this tripod, but there are many others to chose from.
This is more of a courtesy to your own eyes and the eyes of those around you than anything else. Red light doesn't disrupt your natural night vision as much as white and blue lights do. You'll be able to see the ground as you move around, but you won't have to wait 15 minutes after using to see the stars. Any red flashlight will do, but I like this one here.
4. A Focus Mask
We're getting more into the "Nice to have" arena now. It is possible to focus your camera manually using the night view screen. I say possible, but I personally always struggled with that. I got tired of fuzzy, out of focus stars, so I invested in a Bahtinov Focus Mask. This inexpensive tool is remarkably easy to use and gives great results. It works by diffracting the starlight in a predictable pattern, and it makes it very apparent when your star is in focus. You don't have to guess anymore or get "close enough", you can easily get perfect focus in mere minutes. Check out this one here.
5. Star Tracker
Ready to really step your game up? Before investing in a telescope or telephoto lens or even an astro-modified camera, you need a star tracker mount to work with. There are all sorts of tracking motors to choose from, but for the beginner, I recommend the Star Adventurer mount. This is a great mount that can handle up to 11 pounds. It's easy to polar align and get set up, and is compact enough to easily travel to a dark site to shoot. Check it out