Are there guides available at acropolis?

I don't remember if there are guides at the Acropolis. We booked a guided walking tour of the Acropolis from Athens Walks, which we enjoyed very much. Not sure if you would be interested in doing this but thought I would let you know.

You cannot "decide to go on he last morning" any more.... the Acropolis is in such demand that the govt has limited the number of people who can enter at any one time. from May (maybe earlier) thru October. starting from 9:30 daily there are huge throngs of people huge cruise-ship and package-tour groups, so you will be staqnding in line all the way up and down.
YOu will not be admitted if you come on the day without a ticket that states your allowed entry time (you do not hve to exit at any certain time). During all those months you will need to plan ahead and order tickets online! And it is not inexpensive anymore. Greece finally realized their entry prices were far below other European countries, and have increased them. The Acropolis itself is now €30, tho the smaller ancient sites in Athens are much less.

And no, there are not guides available at the door, tho this does happen at major sites on a few islands. If you want to be part of a group tour. One of the best-regarded is Athens-Walks (do not confuse it with other groups with Walk i the title). IF you sign up for them, it can be on the basis of THEM getting you the entry ticket ... on the website you can specifiy this, and if there are no tickets left for that day, they will refund your fee. We are all unpaid vollunteers on this forum so we do not have time to give you all the information, such as various prices -- that's part of your pre-trip homework. I hope you have a bit of time before you go, to line things up ... and we hope you have a wonderful time. Athens has changed, of course, and all of Greece, but it remains a glorious adventure.