Ausbuldung

Hi iam Rita, from Nepal. I am here in Germany since 8 months in aupair visa. Now I would like to do ausbuldung in travel and ticketing. What are the documents needed here and what is the process....? What should I have to do from beginning...?

You should read about Ausbildung (apprenticeship) in Germany, e.g. on https://www.ausbildung.de or similart websites.
In most cases (for most subjects), you need to apply for an apprenticeship at the company you want to be traneined in. This is then similar to a job application. In some cases (e.g. nursing), you need to apply at special schools.