Do you have to make reservations?

Unless you are by yourself and willing to sit at the bar, I would highly recommend a reservation.

If you want a table, reservations is almost a must, even bar space goes quickly. A couple days in advance should be sufficient though.

I called less than two weeks before and didn't have a problem getting reservations

I would recommend it.

No but reservations are hard to get. The odds of you being able to get a table with no reservation is rare.

You don't have to. I walked in but it was close to when they opened. I imagine they get busy most nights.