How do I help newbies generate characters without being in person?

Background: I am about to start running a virtual D&D5e game over Zoom (I don’t have a choice of platform) through the local library. I have invited four of my friends to join, and only one has ever played before (he plays a lvl 5 paladin in my other group and wants to do a paladin or fighter this time). None of them have the 5e books or even know the basics of generating characters.

Usually, when I help new people for their first character, we meet in person and talk, bounce things off each other, banter, interrupt each other, and only then do we even work on the mechanics. However, COVID-19 has made it so we cannot safely do that anymore.

I have access to Roll20, but nobody else does and we cannot use it in game. The library is pretty strict on that. Most communication is done by text, with a little email as well. I effectively have a week to generate 4 characters for 4 mostly-new players before the first session, plus now one for the librarian. We are starting at lvl 7 (that is where the other group is and most will be using the same characters).

How do we generate ideas and then match those with mechanics without being in person?

Update: I emailed the librarian earlier to see if the other players would be willing to make new characters or regress their characters to a lower level, probably lvl 3. I will edit when I get a response. I figure I can point her to all the “start them at lower level” responses here and that should help my case.