The idea of registering misspellings of your domain name is to catch visitors who make a typo when they try to go to your website.
Traditionally, there are two routes people can take:
- They make a typo when typing in your domain name directly in the browser address bar.
- They make a typo in the search engine search box, and search engine serves up the misspelled domain.
For the first route, there needs to be substantial traffic. A good rule of thumb is that your daily visits should be at least 5,000 for direct traffic from misspelled domains to be meaningful.
The second route has pretty disappeared in recent years, as search engines have advanced to the stage where they often can recognize if someone makes a typo. For example, if you type in "aplle.com" into Google or Bing, both search engines recognize that you are really trying to go to apple.com, and shows apple.com in their search results.
For your first domain, you do not need to register misspellings, as you will certainly not have enough traffic to your domain for traffic to misspelled domains to be meaningful.