The ticket is only for admission, no guidance ... and yes we advise being at the ticket-entrance at 8:30 (maybe even earlier, and depending on that day's crowds (you have not told us the month of your visit), they may let you in early.
You successfully accessed The Hellenic Heritage ticket platform, launched in summer 2023 as the official Govt site for online ticket purchase -- this is the link: https://hhticket.gr/tap_b2c_new/english/tap.exe?PM=P1P&place=000000002 Congratulations on finding it!
There are also commercial sites that "look like" the official site -- for example - https://www.acropolis-athens-tickets.com -- but the clue is... this site is a ".com" site, not a ".gr" site, which means it is a commercial venture. Yes, they will get y ou an online ticket but add 90c for the service, and ALSO list add-on options at a cost (audio guide for added €12), and a licensed-guide 1 hr tour for ?? About €37? (12 entry fee/+ guide = €49). I find such websites "iffy" because there are no reviews -- a tiny link at the bottom shows that this is actually a commercial operation based out of Germany (!) stick with the website with the id of .gr.
Since you have not signed up for a group tour with an established outfit like Athens-Walks, Here are some options for getting the most from your visit:
• PRIVATE GUIDE - Licensed Guides (who must study for years & pass rigorous tests) cost about €60 per hour, for a group of up to 4 people; reasonable if you have that number; usually 2 hr minimum.
• D-I-Y with BOOK - Rick's Guidebook gives step-by-step interpretation of Acropolis AND Partheon; best to read beforehand, maybe photocopy to carry along & glance it.
• D-I-Y AUDIO (Free!!) many Rick devotees forget to use this website of his! Go to LH corner and cllick Watch-Read-Listen and click GREECE, and you'll see the FREE audio DIY, to download onto smart-phone. Best to listen beforehand to get an idea of pacing, so you can use it smoothly on site.
BONUS -- Another highlight in the Combo ticket is the Ancient Agora, just downhill from Acropolis - it can look like just a pile o' rocks without help.. but Rick ALSO has download Audio for this ... since it's right there, I would suggest doing this immediately after your Acropolis time, (unless it's a super-hot July day).
NEXT on LIST -- Or, you can save that for later & walk over to Acropollis Museum... to tour it right away, or first go up to its lovely glass-enclosed terrace cafe & have a coffee-break or lunch; good food, moderate price & u look straight up at Parthenon. THis Museum is NOT govt-owned so is not part of your combo -- but admission fee is modest. They used to have audio guides at the desk but do NOT count on them... maybe they've stopped them, or they're all in use. There are several commercial firms -- Get Your Guide and Clio Museum Tours are 2 -- that sell audio tours; check the reviews first.
NOTE for ALL - All commercial ticket-offers make a big thing of "skip-the-line" advantage. This may mean something special in other countries... but for Greek sites it just means you don't have to stand in line at the TICKET WINDOW... if there's a long line outside the actual ENTRANCE GATE, you still have to stand there. (the secret is timing of course).