There are a number of ways to do keyword research without using the Google Keyword Planner.
One way is to use Google AdWords. Go to the AdWords tool and create a new campaign. Then, enter your keyword into the "Keyword Ideas" section. This will give you a list of related keywords, as well as their search volume and competition level.
Another way to do keyword research is to use Google Trends. Enter your keyword into the search bar and see how it has been searched for over time. This can give you an idea of whether or not a keyword is popular, and how its popularity has changed over time.
Finally, you can also use Google search itself to do keyword research. Simply enter your keyword into Google and see what comes up. Pay attention to the results that come up on the first page, as these are the most popular results for that keyword.