Are Sikhs allowed to go to Churches and Hindu temples?

Respected Adhik Ji;

Sikhi clearly states, the Creator is everywhere, including the religious places of any and all religions. But Sikhi also states that the creator is not limited to any four walls of the building.

It all depends upon the reason one is going to any place of worship.
Please refer to the following verse from SGGS,

Please refers to the following verse from SGGS.
ਹਿੰਦੂ ਪੂਜੈ ਦੇਹੁਰਾ ਮੁਸਲਮਾਣੁ ਮਸੀਤਿ ॥
ਨਾਮੇ ਸੋਈ ਸੇਵਿਆ ਜਹ ਦੇਹੁਰਾ ਨ ਮਸੀਤਿ ॥੪॥੩॥੭॥

This shabad is by Bhagat Nama ji. and the spirit of the meaning is:
different faith groups pray to their God in their religious places,
(But) Nama is praying to that (Creator) which inside neither of those places, (meaning which is not confined)