Even if your mother tongue is English or not, or if you have a degree in education or not, you can still volunteer as a teacher in one (or more) African country.
As you know, going into mobility is not only registering for it. You have to go through an interview and you have to be accepted for it, similar to a job interview, but funnier and more informal. For this mobility, within the interview, you will have to go through a language test as well, where your capacity will be our main focus.
Don’t worry, we will not expect you to be a Harvard student, you will most probably teach kindergarten pupils, but you must have some knowledge.
For a similar experience, check out this kind of mobility here.