Dear Victor woha,
Thank you for reaching out to the Wefugees Community!
In general, there are several options to make the Abitur at a later date, even years after you finished the "Realschule". You could, for example, get enrolled in a so-called "Abendgymnasium" or a "Kolleg".
Next to the Abitur ("Allgemeine Hochschulreife"), there is also the option to make the "Fachabitur" (Fachhochschulreife). This would qualify you to go to the "Fachhochschule" (where you can also study for Bachelors and Masters and is more practical oriented) and even some selected universities later.
I recommend you to get some counselling at your local "Arbeitsagentur". I am sure they will be happy to support you in this.
I hope this helps and do not hesitate to get back to us with any further questions.
All the best,