Do you think it makes sense to try to learn TDD on a language you don't know ? So let's say I want to pick Go (as a hobby, not for a particular professional need in the short term), would it make sense to try doing some TDD on my first smallish applications ?
I don't think there is anytime not to try to learn it. It will be harder the more unfamiliar you are with everything else (language, libraries, domain, etc...)
On a side note. You will never learn TDD from a video. If you want to learn TDD, get very familiar with testing in general, pick a domain you are comfortable with and then force yourself to write tests for everything before code. Repeat 2-3 times and you will be better at TDD than 80% of the people who are presenting on it.