There are a large number of types of polls/activities you create in Poll Everywhere to get more participation. To learn about these types of polls please visit this site.

If you are going to be grading students you must use Multiple Choice polling. When setting up a poll like below you can click on the check mark next to an answer if you want to indicate a correct answer, you may choose more than one correct answer.

Pro Tip: Put your polls into folders by class session to make finding them easier, you can do this with the drop down box at the bottom of your poll.

Once you have created your activity you have the ability to edit settings.

Visual settings: This button opens the Visual settings menu that you can use to customize your poll. There are many options to ensure your poll matches your presentation. To learn more about the Visual settings check out the Customizing your poll section of the Presenter guide.
Activate: This button will activate your poll. The activation icon looks like a smart phone sending out messages. For detailed information on accepting responses, view the Activating your poll section of the presenter guide.
Show Results: This is used to show or hide an activity’s live responses. Depending on the type of activity the popup tool tip may say Show/Hide chart, Hide/Show Text Wall, etc.
Lock: The padlock icon is used to lock your activity, preventing anyone from responding until you are ready.
Clear: The file box button can be used to clear previous responses to your activity. You can visit the Clearing Responses section of the presenter guide for more details.
Fullscreen: The icon with four outward facing diagonal arrows is the fullscreen button. You will use this button to enter fullscreen mode to Present your activities on the Web.

You have the ability to assign point totals to questions by clicking on the Edit in the bottom right of the screen shot about.

Then you must click on "assign points to different options".

If you wanted to give out participation points for coming to class for example, you would mark each option as correct and give each option a point.