Dentistry is a competitive field, dental schools are looking for students who can take on a tough science course load, a dedicated background, so pick some activities that you realy like and stick to them. Schools look for well rounded students, so beside doing well in school and DAT, they want someone who excel outside of the classroom, perhaps you won a volunteering award, or have been playing piano/violin at a high level.
While schools want applicants to have the above, they want personalable applicants who can do business. So it's a real mix. I just listed some for general guideline, but what exactly are schools looking for? it differs from school to school.
Just be yourself, pursue your interests and excel in anything you do 😀
Good luck