Buy

GoPro HERO 7

Do not buy GoPro HERO 7 for hyper smooth stabilization

Older GoPro cameras: HERO4, HERO5, HERO6 with gimbal are doing a much better job. You can find a lot of videos on YouTube where people are comparing the hyper smooth stabilization from GoPro hero 7 with the older GoPro camera on a gimbal and the gimbal stabilization is much better.

How to get better quality videos with GoPro HERO 7 camera

GoPro HERO 7 camera straight out the box is not recording the best possible video quality. To get the best results you have to change some settings. I was testing different settings for the last couple of days and the best results I had when I was recording 4k 25fps (with 24fps I got the flickering problem under the artificial lighting) what gives me nice motion blur and these settings:
FOV: "SuperView" is doing much better than the "Wide" setting, you can correct the distortion in the postproduction if you don't like this fisheye look.
Stabilization: Auto
Protune: On
Shutter Speed: Auto
EV comp: -0.5
White Balance set manually depends on the weather - What is the color temperature. You can set this to "auto" but sometimes the camera is going crazy with the color temperature during the recording like you can see on the timelapse from the GoPro camera in the video above.
Min ISO: 100
Max ISO: 400, I am using maximum ISO 800 for dark situations but anything above that is giving too much noise.
Sharpness: Low
Color: Flat
This allows me to color grade and sharpen the video in the post-production but if you are not going to edit your video you may want to set sharpness to "Medium" and color profile to "GoPro".
RAW Audio: High
Mics: Auto
This was the best audio settings for me so far. I am going to record a lot with GoPro HERO 7 camera now and if I change any settings I will let you know.

Here is how some of the YouTubers set up their GoPro cameras

You can find GoPro cameras available on Amazon and prices here: BUY GOPRO CAMERA HERE

GoPro Accessories

Micro SD Card

The GoPro camera requires a micro SD card which is not included with the camera. To be able to record videos in 4k resolution, you need the fast micro SD card - minimum 30 MB/s write speed.
Here are some recommended micro SD Cards for GoPro camera:

Battery

If you are recording a lot of videos or you are traveling a lot, you will need at last one extra battery for your GoPro camera. Original GoPro batteries are not very expensive so
I definitely recommend you to buy original one instead of cheaper third party batteries. BUY BATTERY HERE
You can also get Dual Battery Charger, it's expensive but one battery and USB C cable are included and you don't have to charge GoPro batteries one at the time in your GoPro camera. BUY CHARGER HERE

Case and Protection

This accessory kit is very useful and not expensive, definitely recommended.

Waterproof housing case for GoPro Hero 7/(2018) 6/5 waterproof up to 45m, GoPro HERO 7 Camera without housing is waterproof up to 10m.
Travel Case
Screen and lens protectors
Silicone sleeve and lens cap
Anti-Fog inserts

GoPro Necklace Silicone Sleeve

This original silicone sleeve from GoPro looks very nice and it's well made but it's expensive. That's why I don't recommend you to buy it.

Cheap Accessory Kit for GoPro Cameras

This third party accessory kit is very cheap comparing it to original GoPro accessories.
All accessories in this kit are made of poor quality materials but some of them I found useful.

Window Mount - not keeping the camera in one position.
Mount Adapters - very useful, allows mounting GoPro camera on almost any tripod.
Bicycle Mount - useful for normal cycling, you can use it to mount the camera on any bar.
Wrist Band - not bad quality, rotatable mount, somehow useful.
Selfie Stick - bad quality, easy to break, useful.
Clip Mount - not bad quality, very useful.
Floating Grip - very useful, may save your camera.
Head Band - good quality, very useful, I am using this most of the time. Similar quality comparing to original GoPro headband.
Chest Strap - good quality, very useful, the best for cycling.

It's hard to recommend this because of its quality, but if you'd like to buy it, you can find it here: Cheap Accessory Kit for GoPro Cameras