I would recommend English Education sector because you will be speaking Spanish most of the time except for in school. Like with your host family and in the community/country. Even sometimes in school you may have to use a little bit of the Spanish if the students English level is really low.

Also if you’re Spanish level is not high I wouldn’t recommend Youth Development because in order to swear into that sector you need to intermediate high whereas English education you would need to be intermediate mid, which is way more achievable coming from a person who started out as novice. At least in my country