Fusion 360 Robotics Toy

i have a design of a toy which is a pet dog in fusion 360. The motion mechanism has not worked and its not bending, sitting, standing, dancing the way I had planned. So the structure needs to be modified , any electronic parts, gearing, motors may need to be replaced to make it work.
I am not very familiar with simulation and its capabilities but this is what we should have done fully prior printing and assembling. Its assembly process is also hard so quick snap and fit type of assembly will also help.
If you can help with this, then i can pass on fusion 360 full project.