I'm trying to renew my green card and have a question about 5a and 5al on the I-90 form, page 3. Not sure what they are looking for.

How did you get your green card? Did you do Adjustment of Status in the U.S. Or did you get an immigrant visa outside the U.S. and then enter the U.S. If you got an immigrant visa, you need to enter Part 3 #5.a.1. where you entered the U.S. and in Part 3 #5.a. what your destination was (i.e. where you went to live) on the trip when you entered. If you did Adjustment of Status, you skip Part 3 #5.