You need to do FAFSA for federal loans. Just say no.
CSS for need aid.
Loans can strangle your future. Look at the CS kids today from top schools - can’t find jobs.
Go where you can afford even if the name isn’t as well known.
Btw BU is need aware I believe - this means they can reject you on the basis of finances (if you need too much). Far less than half of BU students get need aid. It’s possible but they may seek first generation, those they believe are minorities and more. Relatively it’s a school for the wealthy but like Wake and Tufts, they mix in high need kids - moreso than Wake and Tufts but less than other schools.
It’s too hard to know. It has a very low acceptance rate.