Etiquette of the mosque
Before leaving for masjid, you should make wudhu, after that leave for majid, If you are in condition of napaki then ghuls is most for you. First of all you should do guls after that you should leave for masjid.
Before corssing the gate and enetreing the masjid you should recite darood sharif and following dua.
اللهمفتة لي أبوابا رحمتك
(Oh God, you have opened the doors of your mercy for me ).
When you are reached inside the mosque and If there is left time for fard namaz then donot sit idle there but first pray 2 rakah tahiyyatul masjid, if there is any prescribed sunnah for that prayer then pray that sunnah prayer.
When you are in mosque then don’t make any kind of noise but keep yourself busy in the remembrance of Allah by doing dhikr of Allah.
When you are coming out after fard paryer then donot forget to recite the following dua.
Allahumma inni as aluka min fadhlika.