You will be directed to the website Fliiby, before you can download the template you will be viewing an advertising (the same style as Youtube, you can skip it after 5s). After on you will be able to download the file.
If you get this warning, most of the time the link to the font is included for you to download it. You will just need to install the font after downloading it or you can use another font of yours choice.
This warning will inform you that the project was created with an older version of After Effects or with a Mac/Windows After Effects and it needs to convert it to your version of Adobe Effects. Nothing will change in the project.
Most of the time you will simply need .to go to the composition "Background" or "BG" and hide all the layers visible there in order to have a transparent background.