systeme.io gives you the ability to create online courses and sell them through your 'creator store'. The advantage to selling the courses on your systeme.io platform is that you keep 100% of the price. With platforms like Udemy you only get around 30% of whatever they discount the course to.

I have my courses on Udemy and Systeme.io whenever possible. There are other platforms you can pay for but training courses seldom earn as much as the gurus suggest in the adverts. So if you are going to create courses you will be well-served to do it on systeme.io which you are maybe using a paid subscription on (you can have some courses on the free membership).