Ausbildung selbstständig?

The tax class is completely insignificant for a possible self-employment, because it is only required and awarded as part of the wage tax deduction.

From that you are not 18 yet:

First of all, you need the permission of your parents and the family court.

If your parents agree, you have to submit an application to the family court (former court of custody). This is formless, i.e. there are no finished forms or similar. The request describes the wish that the minor (so you) would like to make himself self-employed. The application must be signed by your parents.

Approval according to § 112 BGB usually presupposes a personal appearance of the minor and the legal representatives at the family court (no exceptions are known).

There is no such permission. Without a positive opinion from the school and a well-founded business plan, you can immediately reduce the idea.

If the permit is present, you must register your commercial activity with the competent municipality and the tax office in accordance with §138 AO and §14 GewO. For the latter, you must fill out a questionnaire for tax collection (FsE) and transmit it electronically.

The tax office will then check the inputs and assign a tax number to you.

If you expect more than €2,000, the small business operator scheme according to §19 UStG is not eligible. If you’re not a small businessman, you have to go on 10. Upon expiry of the pre-registration period, the sales tax pre-registration is issued to the tax office.

No matter how in the end, you will have to make your income tax declaration annually and with Appendix EÜR, depending on the approach of the FA, also the VAT Declaration and USt Declaration.

If you do not register your business, this is an offence and the tax office will not find it funny.

Why do your parents always have to be in the boat?

Legal basis is § 112 para. 1 BGB. A minor then needs the consent of the legal representative(s), as a rule of the parents, and the approval of the court.

You are over 18, for forget the part with the parents and the court.