Twitter Feed

of course there are many plugins do that, search the plugin repository https://www.ads-software.com/plugins/
those plugins gives you a widget you can place on your sidebar or any other widgetized area of your theme.
i found this one seems simple.
https://www.ads-software.com/plugins/really-simple-twitter-feed-widget/screenshots/

I have added a few twitter widgets but none of them appear on the site when I add them…

you need to install the plugin, then place the widget on your sidebar and fill the widget with the required information.