Welcome to the Wefugees Community and thank you for reaching out to us.
I am not an expert on student/vocational training ("Ausbildung") visas and I think we may need some more information as well in order to give you a reliable answer.
Are you holding a residence permit according to section 16a "Vocational training; advanced vocational training" of the German Residence Act?
I was reading the section again to look for some information on "changing" the vocational training - in 16b (4) it says:
(4) Bevor die Aufenthaltserlaubnis zum Zweck einer qualifizierten Berufsausbildung aus Gründen, die der Ausländer nicht zu vertreten hat, zurückgenommen, widerrufen oder gemäß § 7 Absatz 2 Satz 2 nachträglich verkürzt wird, ist dem Ausländer für die Dauer von bis zu sechs Monaten die Möglichkeit zu geben, einen anderen Ausbildungsplatz zu suchen.
The translation would be something like: "(4) Before the residence permit for the purpose of qualified vocational training is withdrawn, revoked or subsequently shortened in accordance with § 7 paragraph 2 sentence 2 for reasons for which the foreigner is not responsible, the foreigner must be given the opportunity to look for another training place for a period of up to six months. "
So it doesn't give us any information on the regulations in case the foreigner is voluntarily (or reasons he/she is responsible for) quitting the vocational training in order to start something new.
I think it will be also relevant to know if the job you want to learn in the IT-field belongs to the so-called "understaffed professions/shortage occupations" as nursing for sure is. So maybe you can specify a bit more. To be on the safe side, I would recommend you to contact the immigration office (Ausländerbehörde) directly and ask for the requirements.
I will also link two colleagues here who may be able to give some more details or an advice. Dear @mbeon-Gabriele or @mbeon-Éanna, would you agree with me or/and can you add anything here?
In any case, please don't hesitate to get back to us with any further questions.
All the best,