Icons can be downloaded or drawn by yourself. Figma works with a vector with a bang, so it can be safely used for these purposes.

On shutterstock.com you can find a lot of icon sets (paid). True, the icons there are in EPS format, and Figma does not work with it. That’s why I’m converting icons to SVG.

Game simulator for building Bezier lines – a game to help you master the pen tool.

More icons:

Figma files with icons

In order for the icons to be correctly resized (the thickness of the lines changed depending on the scale), you need to convert them to a vector with a stroke using Outline Stroke in Figma.

How to make

The Complete Guide to Iconography (ru)