Hi Snade 17,
Two groups of people stand out against the general trend of spending leisure time in Bulgaria. On the one hand, young people attending = attend fitness gyms and places of entertainment, and on the other hand, people with/on higher incomes (who) prefer to spend the night at the theatre, (or the) concert hall, or (the) cinema. As for the weekend(s), the latter attend the (beauty parlors) in England it would be hairdressers, or beauticians or travel within the country or abroad.
() = not necessary It is not always necessary to use fitness when talking about gyms but it is not incorrect.
in/within = Depends if you are talking about within Bulgaria or in the local country/countryside
Hope this helps. Good try.