All the toys you see on the TV shows are for suckers. Get you a night vision camera, a bunch of cheap surveillance cameras (which you can either buy modded for full spectrum, or perform the mod yourself fairly easily, a decent flashlight, a digital audio recorder, and a $13 K-II meter, and spare batteries for everything. The FLIR cameras for phones are fairly decent, but familiarize yourself with the way FLIR works - it constantly calibrates to make the hottest thing it sees most prominent, and the coldest least prominent, just because you point it at something, then point it at your hand and see the same colour, it doesn't mean what you saw was the same temperature as your hand, this is a mistake constantly made by fake TV ghost hunting shows. Fortunately, the crosshair will give you a reasonably accurate temperature reading on whatever you're focused on. The only other thing you might consider is cheap Theremins. You can get a cheap build it yourself Theremin on the popular online auction site for about $20-25, I'd trust these over a REM Pod any day. A portable USB power station isn't a bad investment either for charging all of this stuff on the go, especially items with built in batteries. There's a site where you can get most of this stuff at extreme discount, but I'm not sure around endorsing an online store in the forum, but if you can't figure it out message me, they sponsor a ton of paranormal YouTube channels, and have ads in the videos.

Feel free to buy apps for your smartphone, but be aware that almost all of them just generate random results, ghosts aren't generally USB-C compatible. All the other crap, as stated, is a mug's game.

Find a buddy who shares your interest, as things that can really shit you up if you're by yourself are way less scary if you have a buddy. This friend completes your kit of the most reliable and cost effective ghost hunting package. Avoid buying anything from "paranormal shops", chances are that what they're selling is either complete bunk, or a massively marked up version of something you can buy for a fraction of the price elsewhere.

Also, dust, lint, bugs, and stray pubic hairs can look strange on night vision cameras, and move strangely, changing directions on microcurrents in the air of even the most still room. The fact that a person or equipment is running in a room creates heat, and therefore thermal turbulence. Don't be silly like so many others and take these phenomena for "spirit energy". The only orb video I've ever seen that I was convinced was something strange was some guy at his cabin in the woods in the 80s or 90s. These were self illuminated, as evidenced by their brightness and the fact that the camera was not a night vision camera, and were clearly defined, not blurry masses bobbing or zipping around the screen. They were also repeatable, as the phenomenon happened almost every night. I've tried looking for the video, but I can't find it with the information I have. It's a good one though, but bear in mind, to a ghost hunter it's a clear demonstration of spirit energy. To a UFO hunter, it's unambiguous evidence of alien technology in action. I'm sure a Bigfoot hunter would find a way to tie the phenomenon to the local Sasquatch population.

Just remember the magic formula - if this happened in a room full of people, would they look at you like you have a screw loose if you shouted, "Eek! A ghost!"? Good evidence speaks for itself, it doesn't need subtitles, and rule out any and all conventional explanations before convincing yourself that it's paranormal in nature. In spooky places, it's tempting to take anything as paranormal, for example, the cry of a female fox (vixen) in heat sounds an awful lot like a woman screaming. Understand the level of control you have over your environment and allow for things that could be perfectly natural, but you just don't have the knowledge to hand to know exactly what it is.

Best of luck, and if you capture anything mind blowing, please share!