Hi @Lily
Yes, you can change to a residence permit for studying without finishing your Ausbildung. You apply for it at the Ausländerbehörde once you have proof of acceptance to university. You do not need to apply for it at a consulate.
When showing you have enough money, then you need a blocked account. A bank statement with enough money is not enough. However, there are other options for financing such as someone else providing a commitment to financially support you (Verpflichtungserklärung) or getting a scholarship. This site has more information about this:
https://***.study-in-germany.de/en/plan-your-studies/requirements/proof-of-financing/
Best,
Éanna