E-learning platform: plugins to perform desired functions

I need your help identifying the right plugins to achieve my desired functions on an e-learning platform that I’m developing for a client. The platform is to be like italki.com

Below are the functions desired to be implemented on the platform

  1. An e-learning platform whereby languages professionals can register as tutors;
  2. Students can register and choose a tutor to learn from based on their language of choice;
  3. Students can purchase credits which will be used to book their tutors;
  4. 15% commission is deducted from each course session fee as service fee, and 85% goes to the tutor;
  5. Tutors can withdraw their money once their wallet is up to $ 100.

please developers, help out