When considering college, do the homework! One does not buy a house or a car, which carry comparable value, without weighing the pros and cons. As much as students and families want to send their progeny to the best school, "best" is a relative concept. If you struggled in the "regular" courses and nose-dived in honors or AP courses, then highly selective college settings may not be your "best" fit.
On the other hand, if a student has yet to confront any intellectual challenges which unsettled their "mental mettle" then they may want to consider very selective schools here in the US and abroad.
The search hinges on knowing yourself well. Some students are hard workers constantly seeking to best their last showing as evidenced by an exam score. Others know that the last thing they seek is more study and longer study at that. In sum think about how you approach things academic.
Secondly, investigate your interests. Shadow someone who is doing professionally a task or work you know, or think you enjoy. I counseled a student who was certain he wanted to be a doctor, until he sat in on a surgery - he fainted at the sight of blood. Often I coach students who are adamant that they are called to engineering, despite failing physics and calculus!
Finally, visit campuses, whether virtually online or in the area. Many think their ideal is a gorgeous, leafy setting with beautiful old buildings; until they see contemporary edifices in sunny southern California. Ivy grows beyond the Northeast corridor.
The best way to prepare for the admission process is to try it on by applying for summer programs, internships and other opportunities requiring thoughtful renderings of your ideas and in-person interviews. If you hate the dry runs, then tweak your college aims and lists accordingly. Until one has a better sense of self through "testing" the waters in other venues, it's hard to be absolute about the "ideal" setting.
I knew I wanted a venue where I would be successful, enjoy warm weather and have the opportunity to change (my major several times) and my sense of self. As a first-generation student, I also knew I needed a place which would not leave me hugely indebted. Texas worked for me and later that Ivy League setting.
Get to know yourself and then find the niche for your "self" to grow and explore and hone your gifts. Visit campuses and apply for other opportunities and experiences beyond your familiarity and comfort zone. Do your homework-first on yourself and then on the setting that best affirms your gifts and interests.