All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Given its origin, accounting is one of the beneficial sciences, and learning it leads to many benefits in permissible livelihood matters.
Based on this consideration, it is permissible to learn it and teach it.
Therefore, there is no harm on you in offering those lessons and taking a fee for them.
However, in regard to financing, you have to clarify to the students the prohibition of Riba (interest and/or usury), and that there are other legitimate alternatives instead.
You should also clarify to them the danger of Riba and its bad effects on the individual and the society, and that Islam prohibited it and is very stern on this because of its harm.
If you do so, then you are not sinful if the students or anyone of them chooses to work in the field of Riba; the sin falls on him and not on you.
For more benefit, please refer to Fataawa 123923, 84614, 86231, 88593.
Allah knows best.