Duolingo should never be the main tool for learning a language but only a supplement. It's better to follow a structured course, for instance here: https://www.dw.com/en/learn-german/s-2469.
Other good resources for German are:
German with Jenny: https://www.youtube.com/channel/UClBrbJXNh2sFxOuvH4o5H9g
German is Easy: https://yourdailygerman.com/
There's no ultimate answer when one should start speaking in a foreign language. Some start right from day one, others prefer a silent phase and wait until they are upper beginner or lower intermediate. Just do what feels right for you. It isn't easy though to find German language exchange partners.
What you can do, to improve your German now:
- Participate in German discussions here in the forum.
- Write German notebook entries and get them corrected: https://www.italki.com/notebooks
- Take part in the 30 Days Speaking challenge: http://hugginsinternational.com/30dayspeakingchallenge/