In accordance with proper behavior, when a person goes and visits a respectable personality, one should speak sweet words to please the person. Similarly, when visiting the temple of the Supreme Lord, one should offer prayers in glorification for the pleasure of the Lord.
Sri Nityananda Prabhu, the elder brother of Sri Chaitanya Mahapabhu and the very first expansion of the Supreme Lord, is the shelter of all surrendered souls and the most merciful Lord who bestows Krishna prema upon all who take shelter of his divine lotus feet. The verses that one can say in glorification of Lord Nityananda while taking darshan are:
nityanandam aham naumi sarvananda-karam param hari-nama-pradam devam avadhuta-shiromanim
“I bow down to the Supreme Lord Nityananda Prabhu, who is the awarder of the highest joy to all, the bestower of the holy name and the crest jewel of all paramahamsa mendicants.”
nityananda namastubhyam premananda-pradayine
kalau kalmasa-nasaya jahnava-pataye namah
I offer pranama unto Sri Nityananda Prabhu who bestows the bliss of divine love, who eliminates the filth of the age of Kali, and who is the master of Jahnava-devi.