To help astronomers locate the stars, the sky is divided up into
88 areas. These are called constellations. Each constellation is
associated with a pattern of the brighter stars within it, and
consists of a defined area of sky surrounding that pattern. Each
constellation has a name, of course, usually mythological in origin.
Most make their appearances at different times of the year.
When someone in the UK asks us to name a star for them, we always
select a star from a constellation which is visible from the Northern
hemisphere (England, Wales, Scotland, Ireland and Europe) at the
time of year that the registration is dated.
But it can be quite satisfying for you to select a constellation
yourself, to especially suit the person you are naming the star for.
For example, if someone particularly likes cats or horses, they may
be especially pleased to have a star named after them in the constellation
of Lynx - "the Cat" or Pegasus - "the Winged Horse"!