Most fruit trees will grow in Bulgaria except Olives , Lemons and most citrus fruit .I do not know what part you are living in and temperatures can get as low as minus 30 in parts .Also in summer it can reach 40 c in parts . So you need to go for winter hardy specimens which will have a good water supply in summer . Grapes are an obvious choice with Cherry , apple and pear . I have not seen many Raspberry's or Blackberry's but can see no reason why they should not do well .