I am in partial agreement with previous posters. Do what you want, but also be careful. Undergrad is the new high school.
My advice about what to pursue: you like anthropology, go with it. But anthropology seems to be a pretty competitive field because more people pursue the education than there are positions available, and what positions are available often demand an advanced degree – but this probably isn’t so different than most college majors these days. Picking up math or a hard science might be a good idea while you’re an undergrad (in other words, perhaps double major – do one thing you’re interested in, such as anthro, and one thing that you can fall back on when times are tough).
Picking a school: If you can get into a top 20 school and afford it, that’s great. But I don’t think it makes any sense to go to one immediately. If your family is any less than comfortably upper middle class, and/or you don’t get a generous scholarship, I think an expensive private school is a waste. There’s no reason you can’t start at a state school or community college and enjoy two years of low tuition while doing all the stuff that you’re going to need to take later anyway. This is true whether you’re a good high school student or a bad high school student. The first two years of college are almost universally basic core classes that teach all the stuff high schools generally don’t get through to you.
Heck, if you plan to transfer, community college is probably the best way to go. It’s the cheapest tuition and the courses are designed to be as transferable as possible. Very likely the counselors are more helpful at directing you too.
Private schools can be more expensive than public ones by a factor of ten or more, and a lot of people waste valuable years of their lives paying off big debts that could have been at least partially avoided if they waited two years before transferring to an ivy or one of the seven sisters.