How to use the downloaded AE template, how to change text and generate video

Templates usually have many sequences that are not directly displayed. You can go to the material box, double-click those sequences, open them all, and you can find the initial text layer. Then go inside and make changes. It's the same as PS or something, just select and type and it will change. If you want to generate a video, it depends on what format you want.

Most of the time, just go to Composition, click make?movie, and generate it?

The text layer is