What are the most important parts of the college application?
What are the different types of applications I may encounter?
What are some tips for the writing the best college essay?
https://www.commonapp.org/apply/essay-prompts
https://apply.jhu.edu/application-process/essays-that-worked/
Will I use the Common App? Possibly. However, some colleges still require you to apply directly on their own college website portal.
Suggested readings
College is Yours 2.0
Colleges That Change Lives