The graphics used to illustrate the main pages on this site are from Freepik by Stories https://www.freepik.com/author/stories but they are also available free with attribution from Freepik's Storyset site https://storyset.com/how-it-works
In both cases you can choose to animate parts of the image.
The downloaded SVG images can also be edited using the free online editer Photopea https://www.photopea.com/ and animated in more detail with SVGator https://www.svgator.com
Affinity Designer is my design tool of choice. Part of a suite of three design tools, including Photo and Publisher, it is an affordable and powerful tool for editing and creating graphics.
The images for this site were created by adding them as layers in an Affinity Design document and changing the colours using Affinity Design's Select Same Colour tool https://www.youtube.com/watch?v=aPgj7ftbPsQ and then bulk exporting the layers.
Affinity tools are well documented and supported by a comprehensive Youtube channel.