Tracing an illustration in vector and extend

Hello dear artists,

I need this illustration as a vector. It is supposed to be very very similar but it. But it doesn't have to be 100 percent exactly the same. I supply the image as pixels. You can trace it with Illustrator or another program. The shapes should be adopted in this way. The color code can be adopted. The original illustration seems to be drawn. You can also adopt the drawn style a litte bit.
In addition the illustration should be extended. I painted a a bit left and right and at the bottom. Please try to continue the picture there. Just keep painting the zoo wall and add some some brushes and trees in the style.
This project is not very difficult. If it goes well I have more projects in the future to be drawn freely according to specifications.