I published an article in a journal, then I realized that I Can add two other ideas to it and then get it published in more sophisticated journal than previous one. The question is : Can I publish my same previous article (same title, same sections, etc) the only diffrence would be : two added sections that represent about 30% of the article ?
This seems unlikely. I doubt that an editor of a reputable journal would accept it, knowing the details. And it would be an ethical lapse to obscure the details, of course.
You can, however, write an extension of the old work, citing it as usual. But the new results would have to stand on their own to pass review. If they don't, then an option is to continue work until you have something that editors and reviewers (not readers here) find sufficiently "interesting" and novel.