I'm creating a new video project.

I'd like to create the video to look good on social media feeds on mobile devices.
So I'd like to set the aspect ratio.

How do I set the aspect ratio for a video when creating a new project?

Thanks.

when pressing NEW PROJECT there is a window with any standard resolution and framerate.. just select the best your computer can manage (to create the project)
and when rendering select on the "MORE OPTION" part .. the "RESCALE" to have an reduced output for some socials...

usually i made videos on 1920x1080 29fps landscape (and this is the default for Youtube)... but if you want to place for example a video on tiktok you need to create a completely different project (portrait)...

I think the solution from bartoloni is a good one.

I think it depends on the form of video you want to make...but when it is for the social media platforms then you have to create , like bartoloni said, a different project.

Good Luck and tell your experience.