The League of American Bicyclists (our national bicycle advocacy organization) has an excellent of catalog of free on-line courses available via their Learning Center (requires you to create a free account to login). Here is a sample of their offerings:

• BICYCLE FRIENDLY DRIVER – This training aims to educate motorized vehicle drivers about how and why bicyclists travel the roadways in the ways they do with the objective of developing a shared understanding for all users.
• E-BIKE SMART – This series of short videos offers safety guidance on e-bike use, battery maintenance, riding with traffic, sharing trails & pathways and collision awareness.
• LEARN TO RIDE – Learning to ride a bike is an exciting adventure; watch this video to help make the process of learning to ride a safe, effective, and efficient experience for everyone involved.
• SMART CYCLING – Everyday riding skills to ride more safely and confidently; note this course is a prerequisite for their more advanced League Certified Instructor (LCI) training.
• SMART CYCLING TIPS FOR OLDER ADULTS – There are a few additional things to consider if you are getting on your bike for the first time as an older adult or if you are recently getting back to cycling as an older adult.