Theme includes 7 custom widgets. All widgets can be used in standard WordPress widget system in Appearance > Widgets. You can drag&drop the widget on the left side over sidebar option on the right side. Each widget has its settings option and you put as many widgets as you want to the sidebar. Once you change the setting of widget, please make sure you click Save button.
Twitter Widget Option
In order to use new Twitter API. You have to register your application using your Twitter account. Please go to https://dev.twitter.com/apps/ and login with your Twitter account
Create new application then click to create the access token, then refresh the page.
Enter your customer key, customer secret, access token and access token secret to Theme Setting > Social Profiles > Twitter API Settings and you can add Twitter widget to sidebar using Appearance > Widgets