these 2 forms are required
I-485 (adjustment of status)
I-864 (affidavit of support)
these 2 forms are optional, but it is recommended to do them. especially the work authorization if your fiance wants to be able to work while waiting for the greencard
I-765 (work authorization)
I-131 (advanced parole)
if you do submit the I-765 and I-131, these can be in the same packet as the I-485
make sure you read the instructions on the USCIS website for each, as well as the current fees