For tutors delivering lessons online we recommend using Google Meet as the basis of your lessons.
You can easily setup a video chat (providing your device has a camera, of course) and send invites to others. Your students don’t even need to setup an account and can talk to you by voice or through text chat. If your students feel uncomfortable they can easily join without showing their video. Doing a video chat also makes it easy to ‘screen share’ and show pieces of work to your students. Google Meet works well in a web browser on your computer with no additional software or you can download apps for iOS and Android.