Bumpity bump! I have close to zero experience with facebook. Any of you pros care to provide some feedback? Would be much appreciated! 
Amy
Theres a number of ways you could target this, in the end you'll just need to test test test.
I would definitely use a landing page and try to presell things long before getting to the Teachable page. An advantage there is that you can optimise based on the cost per user showing some greater intent, e.g. email capture, clicking through to the Teachable page, etc.
FB can be expensive and a $30 product won't generally convert like hot cakes, so its ideal to have multiple beacons along the way to the conversion.
Also, try targeting people who are considering travelling to Brazil/Portugal - I assume Brazil is available in that behaviour targeting FB makes available.
I would like to add to Zeno's info
(awesome teacher btw) Why not also give a preview of the course? When I go on Udemy I always watch the intro video and a few extra lessons in there to know if this teacher really knows their stuff. You could also do a sign up for something free and then up sell on the next page or email.
Language courses on a CPL are doing great on our network. I think it works well because its a lead campaign (CPL) with an upsell later on when the user is already more engaged with your brand and through retention emails.
Its a two step model, instead of hard selling directly - seems like the way to go IMO based on the numbers we're seeing.
Spain
http://www.abaenglish.com/es/aprende...partnerid=6206
France
http://www.abaenglish.com/fr/apprend...partnerid=6207
Italy
http://www.abaenglish.com/it/imparar...partnerid=6208