Nice to hear from you again.
We wrote an article about the most important things to keep in mind if you wish to marry in Germany (scroll down for the English version):
If you have gathered all the required documents, you can contact Standesamt and let them check if you need to provide anything else and whether you need a legalisation/translation of your documents. Then you can arrange a wedding date with them.
You need to submit your passport in order to marry. Since you are holding an Ausbildungsduldung which is valid till the end of your Ausbildung (+2 additional years if you find a job in a related field), the risk of deportation is not as high as it would be with a regular Duldung, as far as I can see. Keep in mind that it can take up to several months to get a legalisation of your documents. If your Ausbildungsduldung expires because you couldn't find a job that is related to your Ausbildung within 6 months after finishing Ausbildung, then German authorities might deport you. If you are not married until then, it's going to become a problem that they have your passport which they need to sent you back to your home country.
Being married to a German woman grants you the right to obtain a residence permit. You have to apply for it at Ausländerbehörde. In this case you are not dependent on Ausbildungsdulung any longer.