It is not possible to create an environment that will reflect your institution in any of the video conferencing applications on the market. A central recording infrastructure is required to see who is watching.
You want the title of each session to appear below the activity name. You want your sponsors who contribute materially and morally to appear. You want the sponsors of each session to appear separately.
While tens of your members have come to watch, listen, discuss, learn, you want the speakers in each session to be able to download their articles, lecture notes, presentations, spreadsheets in excel files. You want to show links for reference articles. You want to show speakers, sponsors, your institution's social media channels. You want to get the views of the audience by organizing different polls in each session.