Udemy has been a bust for me. In fact, I went on a mini-rant on Twitter this morning about it (https://twitter.com/walkingriver/status/1325772355449344001).

I've had decent success with Gumroad selling directly (https://walkingriver.gumroad.com).

I also sell book versions of the same content on Gumroad and Amazon (https://amazon.com/author/mcallaghan).

I think you should shoot for an hour or two of valuable content onto Gumroad, set a fair price for it, maybe even give away all or part of your first course. Build an audience to give you some fans to sell the second course to. See how it goes.

Good luck!