Preparing for IB/ Learning from others mistakes

I’m a senior in high school, 18 yrs old. I am looking to go to Tcu next year, study finance with realestate. I’m trying to prepare myself for IB, but don’t know exactly how to go about it. Is there anything you guys wish you knew that would of made the overall experience better (internships, more networking, certain tactics) ? I don’t know if I should just go to community and try to get to a target school or transfer to UT Austin? I currently only have 1 connection in Asset management, a executive director at JP Morgan, which is a close friend. I am pretty lost, so if someone could enlighten me it would be great.