1st conduct a small market search, check who's your target customers (geo, nation wide, university....) check competitors, search traffic....
2. Is you domain name good enough?, do you have skills to develop or will you tell someone else to do? SEO and marketing is important too.
3. Doing part time or real business (license)... also mostly banks offers student loans so how will you compete with them, why should they go see you rather than established and trusted banks? Do you have something unique that other don't? All these are crucial question you need to solve before jumping on loan business.`
4. If 1. 2. 3. is positive then have your business plan ready and you need a budget for development, marketing, advertising, business license.
5. Seeks for trusted partners or joint venture to ease your site launch.
Then Good luck.