Icono Youtube:

<a href="https://www.freeiconspng.com/img/18707">aquicon youtube icon</a>

<a href="https://www.freeiconspng.com/img/18707" title="Image from freeiconspng.com"><img src="https://www.freeiconspng.com/uploads/aquicon-youtube-icon-0.png" width="350" alt="aquicon youtube icon" /></a>

Icono Twitter, Facebook e Instagram

https://www.nicepng.com/

Imágenes en general

https://pixabay.com/es/