Prepare Your Device
Storage Space?
Video files are large, compared to other digital data. So you need to be sure you have the room on your phone
Free Up Space On Your Android Device
Disable Notifications
When you are recording a video, you probably want to disable notifications. Text messages, updates from apps, and even phone calls can be a nuisance that adds noise and breaks your concentration while you are trying to film. Both iOS and Android have a Do Not Disturb feature that can help with this
Do Not Disturb (Notification Control) on iOS
Do Not Disturb (Notification Control) on Android
Camera Apps
iOS and Android phones both come with apps that take photos and record video. These will probably do what you want them to.
App Settings
You may need to shift from static photography to video. This is usually a pretty obvious option. (In the Android Example image, "Camera" will take still images, while "Video" records motion picture).
You need to choose a resolution. 1080p might be a good all-around resolution, but if you want or need higher quality (as in the Android Example image), and your device can record it, you can choose that instead. However, that will mean a larger video file.
If you really want higher performance in your videos, and think it worth your while, you can experiment with third-party camera apps available in your app store. They can often do things the native apps in Android or iOS cannot, such as offer more focus modes, or turn-off auto-focus so you can force the camera to maintain focus.
For instance, a popular and powerful app for Android is Open Camera. But if you are satisfied with the native app, it's probably easiest to stick with that.