To access Google+, first log into your your Dominican gmail account. Next, click on the grid button at the top of the page that lists available services. You will see the "g+" icon, and can click on it to access Google+. When you do this the first time, fill out your profile with whatever fields you wish to share.
When you first turn on Google+, you will be prompted to fill out your profile information. Some fields are required, but most are not. So only fill in fields that you truly want to share with people.
Birthday is a required field, so please make sure to go back and set the visibility on this item to "only you" after you initially fill out the form. Below are more detailed instructions for accessing Google+ and setting visibility on profile fields. Note that in the U.S., you must be 13 years old or older to have a Google+ account. Users under the age of 13 will have their accounts suspended by Google.
First, after you have enabled Google+, click on your avatar icon in the upper right of the screen. It looks like a circle. To configure your profile, click on the "View Profile" link.
After clicking on "Your Profile", select the "About" section. Then click on the "edit" link under "Basic Information".
Finally, set the visibility of your profile sections. For example, click "Only you" for birthday so that nobody can see your birthday.
To learn more about Google+, follow these instructions from Google.
After you have your Google+ profile set up, you can use Hangouts. To start a Hangout, follow these instructions from Google.
You can have up to 15 people in a Hangout on the Dominican Google Apps system.