Wasalam
May Allah bless you.
The scholars have a disagreement on the recording and calculation of interest by an accountant.
Some say that this role is not permissible. This is because of the hadith where the Prophet (pbuh) cursed the one who consumes ribaa, the one who gives it, the two who witness it and the one who writes it down.” [Muslim]
However, some scholars say that the recording of the riba is prohibited, only when it is part of the completion of the transaction. Once, the transaction has been completed, the accountant who comes later to do the audit, is not connected to it. He/She is merely auditing something that has already taken place.
I am of the opinion that your training is permissible based on the description you have provided. Also, once you have completed your training, I would advice you to try to join a company that does not deal in haram.
And Allah knows best!