I want to learn German

Hey @Uzoamaka  ,  thank you for contacting us. There are several ways to practice German independently and online. You can find detailed information here: https://handbookgermany.de/en/learning-german#faq_907
If you want to work in Germany, you need a work permit. To get one, you must be considered a skilled worker: https://handbookgermany.de/en/recognition
If your degree/qualification is already recognized you will need to apply for jobs: https://handbookgermany.de/en/jobsearch-and-application#faq_108 
As soon as you receive a work contract/job offer, you are able to apply for a job visa at your local German embassy.
Lastly, I would like to share ALL DIFFERENT TYPES OF VISA and their requirements: https://handbookgermany.de/en/immigration This is a quick way to review your options: https://www.make-it-in-germany.com/en/ If you have any further questions, please let me know. Best Barbara