To say where something happens, say 在 (zài, be located) before the location. Remember to put the location before the verb!
她在家看报纸。
Tā zài jiā kàn bàozhǐ.
She reads the newspaper at home.
我在洗手间跳舞。
Wǒ zài xǐshǒujiān tiàowǔ.
I dance in the bathroom.
狗在那里睡觉。
Gǒu zài nàli shuìjiào.
The dog sleeps there.