Gurudwaras are the holy place of worship for the Sikh religion. People from all backgrounds and all faiths are always welcome into a gurudwara. In almost all gurudwaras around the world, they also offer free food (Langar) and a place to sleep if needed. The people are also extremely helpful and will do what they can to help you out.

EDIT : Please make sure if you visit, that you be respectful of their religion. All you need to do is make sure your head is covered and that you're not wearing footwear. There will most likely be a place before you enter where you can keep your shoes and grab a fresh headcover.