Do they accept walk-ins?

Yup sure do just dont forget two forms of I.D and a recent pieace of mail with your name on it.

Walk-ins only. First come, first serve. Come early to avoid wait times. Eat a healthy meal with 6 to 12 hours and most importantly, hydrate the day before (1.5 up to 2 gallons). Required documents included ID, SS Card and a piece of mail. Wear comfortable, 2 piece outfit and bring a sweater, jacket or blanket.

Yes

Yup just be prepared for a minimum 4 hours your first time.