A new project opens on an empty timeline. Everything you add comes from the panel on the left of the editor, which has a vertical icon rail down its edge.
Upload your own files
Open the Media Library tab and use Upload / drop media, or drag files straight onto the panel. Video, images and audio all work, and so do 3D models in .glb or .fbx form.
Files larger than 8 MB upload in chunks in the background. The clip appears on the timeline straight away and finishes uploading behind you, showing an ⬆ UPLOADING badge until it lands. Do not close the tab before that badge clears.
Once a file is in your library, drag it to a track or double-click it to drop it at the playhead. On a phone, tap it.
Use stock footage
The Stock Library tab searches royalty-free video and photos. Music and sound effects are in the Audio tab. Stock is a Creator and Studio feature: on the free Hobby plan the tab still opens and you can see what is in there, but the search button reads Upgrade to search.
Generate something
The AI Generate tab makes media from a written description. Images and video are Studio only. Voiceover, meaning text to speech, is Creator and up. All of it spends AI credits, and the amounts are listed in the article on how credits work.
If nothing appears after an upload
Look at the Media Library panel. Anything that uploaded successfully is listed there. A failure shows a red block headed An upload failed with a Retry button. Retry before you leave the page: an upload that never lands leaves a clip that is blank when the project is reopened.
You do not have to build it yourself
Put one clip on the timeline, open the AI console and describe what you want. It reads your timeline and does the cutting. That is usually faster than learning the panels first.