I wander between British English and American English.

Personally, I think speaking American English has more advantages, wider scope of application and more casual language, but if the landlord is a boy, I suggest practicing English pronunciation, which is better, more suitable for boys to speak English and easier. If you are a girl, English pronunciation is not recommended, because English pronunciation is more difficult to learn (I personally practice American pronunciation) and English pronunciation is more rigorous. Many native English people can't speak English very well, and English attaches great importance to pronunciation. It is better to speak American pronunciation than to speak impure English pronunciation in Britain in the future.

But in fact, people with pure pronunciation are professionals. If the landlord is only interested, then you can learn anything. Anyway, in the eyes of foreigners, as long as you can understand, language is used for communication. Taking office has no effect on any accent. Don't mind too much. Just buy a professional pronunciation book to practice. Language fluency is the first priority.