Before assigning points, you would need to check the point type options in the General settings first. If these options are disabled, you can not select the point types while assigning points.
To start letting users gain points by doing different activities on your site, assign a particular value of point to each action and enable them.
Step 1: Go to Dashboard > Points & Rewards > Settings > Rewards.
Step 2: Assign point values here. Letting them gain points by:
+ Signing up: When an users register on your site, they’ll get some signup points as a rewards.
+ Posting comment: When user post a comment, they’ll receive point depending on when you allow them to get that point – First time; Once per each post; or Every time
+ Creating a new post: This settings allow users to get points when they create a new independent post on your site, based on the Frequency rule you set, they can receive point the first time they create a post, or every time.
See this documentation for specific explanation of each option.
Step 3: Click “Save settings”