A note of caution, here:-
There's been a fair bit of mention of Teams in recent months. My curiosity was piqued, so I downloaded the .deb and turned it into a portable. Not hard to do; it's Electron-based, and contained within a single directory, just like Skype.
It'll fire-up, and get to the login-screen without issues.....but this is where the "fun" starts. You're asked what you want to use Teams FOR. Education, private use, or business/organization use..? If you put 'Private', you're immediately re-directed to Skype. If you put the latter, the next page then wants to know full 'organization' details; name; type of business; e-mail a/c (so they can check if it's genuine, and see if there's a bank a/c associated with it). M$ will NOT set-up a Teams a/c for anyone unless there's a regular subscription (with associated security/credit checks) bankrolled by a certified, genuine organization.
Top and bottom boils down to this; M$ don't want individuals using it. The student in the example in the first post, is almost certainly going to be using Teams via an a/c bankrolled by his local education authority, and to which he's granted access..... Any individual trying to interact with him for remote education purposes is going to have the devil's own job being able to connect, unless they also have access to a regular Teams subscription paid-for by another organization....
Just thought this was worth mentioning.
EDIT:- It's no good trying to sign-up with a new e-mail and entering 'Education' as your need. If you do this, you then get a 'Sorry, that didn't work. Please sign in with the e-mail already assigned to you by your school". In other words, as I said, the account needs to have already been set-up by an organization.....NOT an individual. Unless you want to go to the trouble of setting up a whole string of 'dummy' organization accounts, that is.....each with an associated specific e-mail account.
(If the above gives you the reponse indicated, they then want you to set up an Office 365 Education account..... For individuals trying to access Teams on their own, the process is all but impossible.)
I'm not trying to pour cold water on the OP's query, just pointing out that Teams is NOT at all easy to access by an individual who is NOT associated with an organization.....especially given his circumstances. And it makes no difference whether it's the browser, or the dedicated client; the responses will be exactly the same.
If the OP's student MUST use Teams, then he is going to have to find an organization who is prepared to let him use their Teams e-mail a/c. Teams is for ORGANIZATIONS, not individuals; it's as simple as that.
Mike. 
After I am sufficiently frustrated, I don't know what version I am using myself!