Advice for aspiring IB/PE in High School?

Hello, I'm a high school Junior and though I'm early to the process, based on the state that recruiting appears to be these days, I want to learn as much as I can about several things:

1. Best unis to apply for placement particularly at BBs/Elite Boutiques/anywhere which would be a good launchpad for a career that is this competitive? I know that school is not the end-all be-all for this, but of course it is still important. For those currently at selective targets/semi-targets what did you do in order to be admitted? What can I currently do to increase my chances of A. admission to these schools and B. bolster my resume with professional experience? Particularly Duke, can any graduates provide insight into what the resources available for those looking to enter the field are? Any other schools which provide substantial resources to undergrads?

2. In these colleges, what is the culture like when trying to land competitive SA positions and other internships? Are you fighting with your peers tooth and nail for these limited spots or is it significantly easier being among people with the exact same professional aspirations as you? Smaller schools like the CMCs versus large targets like Duke/Berkeley?

3. What misconceptions do students like me typically have about finance that are best to know now? I'm attracted to it largely because I feel like analysis is a strong suit of mine and I genuinely enjoy considering all of the factors involved in transactions/M&A/etc. in addition to my work ethic which I know serves me well in a field like this but I would be lying if I didn't say that salary is a massive pull because I can think of positions which I would prefer to finance simply due to the fact that they are not as difficult to enter, the culture is far less intense, and I would seldom have to work 100 hour weeks. Is compensation for hours and effort a pretty linear relationship in the sector or is it gonna be a bunch of years of taking crap from higher-level coworkers for (relatively) modest pay while conducting rather monotonous duties?

Sorry for the long post and the fact that my lack of knowledge is probably showing. If anyone has read all (or any) of this post and is willing to provide insight then it would be greatly appreciated.