Programming

It really depends what programming language your course uses, but a lot of 'embedded' systems are written using the 'C' programming language, so you could start with Harvard University's introductory CompSci course which focuses on teaching the C programming language:
https://online-learning.harvard.edu/course/cs50s-ap®-computer-science-principles?delta=0
(Note - The name is 'introductory computer science' because realistically you need to understand some computer science fundamentals in order to be able to understand programming - especially when it comes to Robotics, which is as much a computer science topic as it is an engineering topic)


A few other C resources which are worth looking at once you've made a bit of progress in learning some programming basics:
Book written by the people who created the C language back in the 1970s: https://www.amazon.co.uk/C-Programming-Language-2nd/dp/0131103628
Lots of useful information about C: http://c-faq.com/
StackOverflow - a goldmine of information about programming: https://stackoverflow.com/questions/tagged/c?sort=votes


Worth looking at Arduino too - they're not too expensive and great for learning about low-level programming: https://www.arduino.cc/
Arduino StackExchange: https://arduino.stackexchange.com/