The honest answer is whoever you like. Different cultures and religions have a set order of who walks down the aisle and if you are strong in that faith then you will be guided on the order.
Who are these honored guests? If you have people who had a stronger hand in raising you like grandparents, aunts, uncles, close family friends and would like them to walk down the aisle we call these Honored Guests. These people are part of the couple’s up bringing and first part of life which makes it great that they are the first down the aisle. You can choose to have a completely different song for them to walk down to as well.
Parents of the couple. You can have both your parents escort you down the aisle. You can stick with a traditional mother walks Groom and father walks Bride in which case you can have the other partner walk down with an escort at this point in the ceremony.
To signify that we are now in the wedding party next to go down would be your officiant. If they are a part of your life, your church, your upbringing, a close friend have them walk down the aisle. If they were hired for your wedding day and are there to make this legal and legit and will be leaving after the ceremony, it is alright to have them sneak up to their spot before the whole processional begins.
Here comes the Groom! He can walk in with the officiant or with his groomsmen, but it is nice to have them walk up to the alter and have someone to great them (i.e. the officiant). If you do not want the bridesmaids to walk with the groomsmen, you can have them follow the Groom and when they get up to the Alter they can give the Groom their best wishes.
Now we get to the wedding party. These are the people you have chosen to stand with you. Who have been and will continue to be a support in your life and relationship. You can have them stand in order of importance to you, in height order, outfit order or if you have a married couple, you can match them up with their partners. The closest to the Bride should be the Maid of Honor. The closest to the Groom should be the Best Man.
The ring bearer goes down the aisle after the maid of honor and best man. They can go by themselves or with the flower girl.
Flower girl/person is after the ring bearer. The petals she is scattering on the aisle are meant for the bride to walk on.
The bride is the big finish, they can go down the aisle with or without an escort.
Remember this is your big day and whatever order you want is the right order.