Fix Max File Size Upload limit in Wordpress

I'm building a Wordpress site, and I'm running into a max file size limit problem when I try to upload files. I'd like to you fix the limit problem, and, beyond that, to teach me how to fix it myself the next time it happens. The specific test for when you've completed this project is that I can use the Divi theme Layout Import function to import a 4MB file. When I try to do the import now, it gives me this error: "This file cannot be imported. It may be caused by file uploads being disabled in your php.ini. It may also be caused by post_max_size or/and upload_max_filesize being smaller than file selected."