There are many tools which you can use for keyword search.
Free tool is Keyword planner (google Adwords)
How to use (google Adwords)
you need to log in first https://ads.google.com/intl/en_NG/home/
Then go to tool then click on keyword planner.
Type the service for what you want to finalize the keyword, Then it will bring all keywords you can easily rank on, then download the csv file.
From there, you can easily know the keywords your blog can easily rank on.
Ubersuggest:- this is the tool you get on neil patel site.
Aherfs keyword tool.