In general, the night sky can be divided into two areas, the northern and the southern sky. Stars in the northern part can only be seen from the northern hemisphere, stars in the southern part only from the southern hemisphere.
All standard and double stars we name are visible to the naked eye all year round on clear nights. The visibility of the star (northern or southern hemisphere) depends on the country you enter during purchase.
With regard to the visibility of the stars, it is important to know that a star is not always in the same place. Due to the rotation of the Earth, it seems that each star "wanders" during the year. The only star that always appears on the same spot is Polaris or The North Star within the Little Dipper which is always directed North. The other stars move around Polaris counterclockwise throughout the year.
Nevertheless, we only select standard and binary stars that, despite the rotation, always remain above the horizon and can, therefore, be seen all year round. This type of star is called "circumpolar star".
The visibility of the constellations is somewhat different. Many constellations can only be seen from the northern hemisphere at certain times of the year. After that, they are only visible from the southern hemisphere. The constellation Orion, for example, can only be seen from November to April. From May to October, it is only visible to the southern hemisphere.
More information about the visibility of all 88 constellations can be found here.