Hi Nour,
Some more information on your situation would be good to have to be able to advise you. How much experience do you have in general with synthesizers? How much with modular? The case you show here above... is that what you already have or is that what you plan to have? What do you want to do with what you plan? What kind of music or for testing purposes, or what exactly do expect and want to do with (the above) modular system?
The more we know, the better we can try to help :-)
Kind regards, Garfield Modular.
For review reports of Eurorack modules, please refer to https://garfieldmodular.net/ for PDF formatted downloads