Find Your Seat Challenge
Ahead of time, create a seating chart on paper with pencil (because it will change), assigning students to seats alphabetically by last name up and down the rows or tables.
Greet students as they come in and direct them to sit anywhere they want, "but don't get too comfortable because we'll be moving soon."
Once class starts, let students know that their first task is to find out where they are going to sit.
Tell them that they are supposed to sit alphabetically by last name, and they will be timed.
The period with the best time and fewest errors will get a prize. As far as the prize goes, maybe go with some negligible extra credit (like 1 or 2 points out of 0) that will look good on day one, but will be a drop in the bucket after a few days.
Once they are all sitting, go down your seating chart list, correct errors in seating. If a student has a special need for seating you can fix that (remember, you used pencil).
If you have older students, you might even throw in an extra challenge like you can't use words.
Ultimately this will help you learn their names, it will productively eat up a good chunk of day 1, and sets a tone for what students can expect.
Astrological Seating Chart Challenge
Greet students as they come in, hand them a sticky note, and direct them to sit anywhere they want, "but don't get too comfortable because we'll be moving soon."
Once class starts, let students know that their first task is to find out where they are going to sit.
Tell them that they are supposed to write their birth month and day (xx/xx style, as in 05/09 from May ninth). Then they are to sit in birthday order so that the person with the birthday closest to January 1 sits in seat #1.
The year you were born doesn’t matter.
Don’t skip seats.