What should a student do regarding a classmate who shows envy and discouragement towards his/her participation in class?

We advise you to strive diligently in your studies, and do not be concerned with the state of this colleague. If you fear that he may affect you with envy or harm, then protect yourself from him with the established remembrances (adhkar), the most important of which is reciting "Al-Ikhlas (definition)" and "Al-Mu'awwidhatayn" three times in the evening and in the morning. This is based on the Prophet's (peace and blessings be upon him) saying: "Say 'He is Allah, [who is] One,' and Al-Mu'awwidhatayn (the two chapters of refuge) when you enter the evening and when you enter the morning, three times, they will suffice you against everything."