Which widget should I start with?

The projectile launcher, unless the lesson is a free-body diagram, an incline, or a collision. Each widget page has its own snippet.

Embed in WordPress

Embed a simulation in WordPress

In the block editor, add a Custom HTML block and paste the snippet. The iframe is the widget. The paragraph under it is the followable credit.

Pick a simulation on the widgets hub, or start with the projectile launcher widget. Classroom notes: teachers. Guide: projectile motion.

Steps

Copy the snippet from the widget page.
In WordPress, add a Custom HTML block.
Paste the whole snippet, including the caption paragraph, then publish.

Projectile snippet to paste

<iframe
  src="https://www.physicslearn.org/embed/projectile-launcher"
  width="100%" height="640" style="border:0"
  title="Projectile launcher"
></iframe>
<p style="font:14px/1.5 system-ui,sans-serif;margin:.5rem 0 0">
  <a href="https://www.physicslearn.org/interactives/projectile-launcher?utm_source=embed&utm_medium=referral&utm_campaign=embed-simulations">Projectile launcher</a>
  by <a href="https://www.physicslearn.org/?utm_source=embed&utm_medium=referral&utm_campaign=embed-simulations">PhysicsLearn</a>
</p>

Other hosts: Google Sites, Canvas, Schoology, Moodle, Notion.