How can I handle WhatsApp

Lately, I want to quit smart phone and I want to use a dumb phone such as new Nokia 3310. Because in my country, 2G connection will be ended day by day. And I need a phone which has 4G. Whatever, I want to ask a question. How can I handle WhatsApp situation. Because we should use it for our works. In my country, if you are working I'm somewhere you should use it. They send some notifications via it. I am a teacher and they are opening some WhatsApp groups and they send some important messages. Also I am studying at a university and if a professor announces something we can learn with class WhatsApp group. For example if a professor cancels a class we can not learn without WhatsApp. So what can I do? I do not want to use some dumb phone which has WhatsApp, Android. Because If I should, I can continue with my smartphone. Because it loses all meaning. I have a tablet, I can check it on it but it is not useful and I can pick everywhere and everytime.