Future Learn provide free online courses, though they will charge you if you want a certificate. Some of these courses are especially relevant to EFL teaching.
Course now available (approx. 4 hours a week for 4 weeks).
Note also that you can usually join courses after they have begun, and as this is an online course you can complete it at your own pace within the timeframe (e.g. you may have three weeks from when you join a particular course).