thoquz

Can anyone recommend a book on modern C for embedded?

Architecture which it targets doesn't matter.

I want to see what are best practices, such as what is done in the generic driver's on GitHub by Bosch for their sensors. (Such as the BMP280)

It's not too late, you can take free courses online about digital circuitry. You can also take any electronic device you have taken apart and just google the part numbers on the IC's, it should lead you to datasheets that explain what each one does and many of them include a reference design so you can rip it off the board and add the components mentioned in the datasheet to make your own gadget! You should also look into microcontrollers, they are very fun and act as a gateway between software and digital electronics, so if you can program you'll enjoy this. There are many development boards on the market and a lot of free software that you can use to program them.