Ask HN: Need advice for changing career

Hi HN, I'm a big fan of HN, and really interested in tech and I have learned a lot here. I'm 27 working as a Business analyst, I hate my job, and I want to get into «serious tech». I have a Bsc in IT management, I'm leaving my job at the end of this month to get another bachelor in Cs & business. (I'll have my business classes credited and will have manily CS classes) : The link is in french https://www.ulaval.ca/les-etudes/programmes/repertoire/details/baccalaureat-integre-en-informatique-et-gestion-b-sc-a.html#description-officielle&structure-programme

I have learned a lot on my job : Done some analysis, software requirements, some html, css, SQL queries, js (hated front end), 3d modeling, just basic tech that I learned on my own.

As I'm starting a new life in september I would love some advice from the HN community : What can I do to beacome a good developer while I'm at school, I want to make the most of it. My long term goals are moving to montreal after my second Bsc. and start an MSC part time at Universite de Montréal in SC, and specialise in AI (even if I sucked at maths I guess I can better with Khan academy). Thanks!