The following options could be used for students without Internet access.
Several companies, including Spectrum and Comcast, are offering free Internet service for a limited time to K-12 and college students who do not have Internet at home: students could explore these options to get 60 days of free Internet access in order to continue coursework online. Many phone companies are offering unlimited data to some or all customers, so students could use their smartphones for things like web-conferencing without needing to worry as much about using up their data. Here is a document outlining what the offers of many Internet service providers and phone companies in response to COVID-19.
This may not be an option for all students, as they may live in an area with limited Internet service.
If a student does not have Internet, but have access to a phone, you could conduct coursework with them over the phone.
Students can also call in to many video conferencing meetings (including via Google Hangouts and Zoom) by phone, using the phone number provided. You would just need to verbally describe things you share on the screen (presentations, etc.).
Finally, if need be, you could conduct coursework by mail, like a correspondence course: you could send resources to students, and they could send responses back to you.