custom components?

Is it possible to make my own custom components that looks something like this?

Yes that’s possible. You have full access to all HTML elements and can style them with css

Can you show me where I would be able to edit that?

https://foojay.io/today/how-to-style-a-vaadin-application/

Here’s some docs about creating custom components based on HTML elements and Vaadin components: https://vaadin.com/docs/latest/create-ui/creating-components/composite