Ultimately, if you don’t have any research experience and do not have time or do not plan on being part of any research, focus and invest time on your clinical experience as well as volunteering and community service. Also, work on maintaining a good GPA and improving your MCAT score.
As previously mentioned, at the end of the day, the sum of all your experience and how everything in your application connects and aligns in a clean and clear manner will determine your success in getting accepted. Keep in mind, though, that MD-PhD candidates do need to get involved in research before applying, and a big emphasis should be placed on research in these cases.