Find the files you want to use for your video in the file browser that pops up
Alternately, click and drag you files on top of the import media to add them to your project
you can add audio, video clips, and still pictures
Once you have media in your timeline, adding more video clips or pictures should be done by dragging it in line with the media already on your timeline
You can also extend or shorten clips by clicking on the edge of the clip and dragging it one direction or the other. This is useful for altering how much of the clip you include in your project
Placing clips one after the other in the timeline will result in what is known as a jump cut. That means that there is no transition effect, and when one clip ends the next begins. One of the most common transition effects is called a cross dissolve. To add one between two clips, click in between the clips and press command + t. This automatically puts in a one second cross dissolve between the two clips
If you want the dissolve to be longer, you can double click the cross dissolve symbol and adjust it, which allows you to apply that change to just the selected dissolve or all of the dissolves in your movie
Alternately, you can go to the transitions tab above your media library, where you will see more transition options that can be added to your movie, such as fade to black, cross blur, etc. Any of those can be dragged into your project and edited in the same way as before
To add text and titles to your movie, go to the titles tab above the media library. Any of the styles and options there can be dragged into the timeline to be added. Keep in mind that they can be dragged above a clip to have the text added overtop of a video clip
In iMovie, it is easy to edit the volume levels of both included audio from your video clips as well as independent audio
In the timeline, you will see the audio for a video clip as the blue bar with a waveform below the preview of the video clip. There is a line that runs across it, which when you hover your mouse over it shows an arrow up and an arrow down. Clicking and dragging that line up will increase the volume of the audio, dragging it down will decrease the volume of the audio
Sometimes, you will have audio from your video clips that you do not want at all. You can remove the audio by right clicking the clip and selecting detach audio. This separates the audio into a separate item in the timeline which can then be edited independently or deleted altogether
Once you are satisfied with your project and are ready to export it, select everything by pressing command + a. Then go to file > share > file...
Clicking on File... you will see a new dialogue box pop up with information about your movie. You can change the title, format (video + audio or audio only), resolution, quality, and compression type
Changing these settings will likely change the estimated render time and file size, which you can see under the thumbnail of your movie. I recommend changing compression type to better quality. If file size is no concern, I also recommend changing the quality to best (prores). This will result in much larger files, but they will be higher quality. Once you are satisfied with your settings, click next and confirm your save location