Hi Jane,
There are different types of software and plugins available on the internet for live chat features. Each software has its own advantages and disadvantages.
Here I am suggesting you some of the most popular live chat software as well as WordPress plugins:
To add chat functionality, you can use plugins like Tawk.to or LiveChat for easy integration. For an opt-in form, try Mailchimp or OptinMonster. Both have simple setup processes and integrate well with most website platforms.