Hi,

For this either you can use default signup option in odoo or you can create a custom form for the user/student registration. You can choose in which way, you need to go forward.

If you are using the odoo sign up option, you can check  the web_auth_signup function in this file /odoo/addons/auth_signup/controllers/main.py .

From the above methods, you can get the function from where which the user/partner is created, by overiding the same you can create a student too.

Thanks