Along with the inbox on Gmail, there are also options to called "chat" and "meet"
The chat option gives you the chance to send a quick, almost text like, message to someone if you want the conversation to be less formal than an email. To start a chat, click "New Chat". This will bring up a smaller menu, where you can type in the email of who are want to start the chat with. You can also create a "space" which is a chat with multiple people, similar to a group email. Once you have decided who you are going to chat with, select the "start chat" button. This will change the screen to almost a text message format.
The meet option is similar to the Facetime feature on an iPhone or a Zoom meeting. This sets up a face to face call. You can set up meets on the Calendar app as well.