it is essential that you apply for your visa at the correct embassy and not simply at an embassy of your convenience. Otherwise there is a serious risk that you will be refused entry at the border
Border guards will ask you questions about your travel plans and can also ask for proof (i.e. hotel bookings, rental car arrangements etc.)
Be prepared to explain your travel plans to any border guard upon entry

If you are planning to visit only one country, you need to apply with that Member State's embassy

اذا كنت تنوي زيارة بلد واحد استخرج الفيزا من ذلك البلد

If your visit includes more than one country, you need to apply with the Member State that is the MAIN DESTINATION of your visit