Your resume is arguable the single most important part of the application process. A well-organized, relevant resume will set you up to get an interview, while a poor resume will get completely lost in the sea of applicants. This is a fairly modern concern, as job postings now get thousands of online applications a day.
If you have major gaps in employment, there are a few ways to make them less noticeable like a change of resume foramt. It is important to be honest about gaps in your resume and not try to cover them up, but to also make them seem productive and intentional. Adding volunteer work or classes in the time you were unemployed is highly valuable and fairly simple to get starter with.