One of the best ways to learn Japanese is to put yourself in an environment where you have to use only Japanese.
However, if you do not have a good foundation in spelling and vocabulary, we recommend that you choose a bilingual instructor who speaks both Japanese and your native language (e.g., English), as one-on-one private lessons are likely to be a better learning experience.
On the other hand, if you have the vocabulary but have not had the opportunity to practice, we recommend that you practice conversation in Japanese only, without using your native language as much as possible.