To provide learning support to students, Google Services apps viz. Google Classes and Google Hangout can be used to teach the students.
Following are the links of user guides for basic know how and to conduct classes online.
Google Classroom User Guide
How to create Google Classroom in Andriod
Google Hangouts Tutorial
There are many video based collaboration services available e.g. webex, Zoom, Loom, Skype etc. Google has both the component and it is free for education.
These services are now very well integrated with gmail account, just login and click on the top right (multi dot icon) and you will get multiple apps and these two services are listed there.
Please use following link to proceed:
https://accounts.google.com
Please use the following:
1. Google Classroom: It works like LMS (learning management system), you can share any type of document (doc, ppt, pdf etc.), create assignments, share links, conduct online test (assessment). You can create multiple classes as per your requirement.
2. Hangout: This service is for the live video interaction with your students. You can run this along with the google classroom or as per your requirement and convenience. Here also you can share multiple things (including your laptop/mobile screen) with your students along with your live video
https://teachercenter.withgoogle.com/first-day-trainings/welcome-to-classroom
https://www.maketecheasier.com/google-classroom-tutorial/
https://zapier.com/blog/google-hangouts-video-calls-guide/
https://edu.gcfglobal.org/en/googlehangouts/