"KiCad is a free and open-source electronics design automation (EDA) suite. It features schematic capture, integrated circuit simulation, printed circuit board (PCB) layout, 3D rendering, and plotting/data export to numerous formats. KiCad also includes a high-quality component library featuring thousands of symbols, footprints, and 3D models. KiCad has minimal system requirements and runs on Linux, Windows, and macOS." - KiCad docs
There are quite a few different alternatives when it comes to electronics design, at the moment we are using KiCad. Long term we want to try and increase the amount of electronics design which we do within CAESAR.
To start learning: it is suggested to start by looking through the KiCad docs, then one could look through the discovery page. After which, one could: practice by doing, watch tutorials, read books, etc.
If you want to start somewhere, you could (schematics):
Currently there is a PCB design branch on the wiki, making it possible to share the design between members, simultaneously allowing for version control to be implemented.