Hi @Willa1980,
I need to confirm the leaving workflow, but for the most part is should be as follows.
First, I would assign others to be project admins BEFORE you remove yourself for obvious reasons. To do this, click your thumbnail in the top right corner of Fusion Team and select Admin.

Once in Admin settings, select Projects and then for each project you can Manage Roles and assign different user admin privileges. Once that is set up, all you need to do is visit each project yourself, and in the Activity Feed should be a "Leave Project" button. (You need to hover over the Joined Project button for this to appear)

Then, once everything is set up with the new admin, they can go back into Admin settings and select Members. Under your name, they can deactivate you. The only thing I am unsure about which I need to verify is the impact that deactivating you has. I believe it will fully remove you from the Team Hub. I am unsure if this affects any data that you have put into the team hub. My gut tells me this is not the case, but I will confirm.
Thanks,
James Youmatz
Product Insights Specialist for Fusion 360, Simulation, Generative Design