You have quite a bit of freedom in how you do this. You can do this collaboratively with your partner (i.e., together, you create one lesson) or you can work separately and create two different lessons.
Here are some examples of what others are doing right now:
You can create your online lesson on any medium that you choose (e.g., YouTube, a website, etc.). Google sites is particularly user friendly, so if you are new to creating a website, I recommend that you start there. If you are having trouble, reach out to me as I have experience in this area. Once you are finished, share your online lesson with me on google classroom.