Most hotels organize the trips, but I would recommend you to take a bus in North Station which leaves you in the entrance. It is way cheaper and you can stay there all the time you want (tours only offer you kind of an express visit).
When you get hungry, you need to go to the restaurant “la Gruta”. It is actually a beautifully decorated cave where you can enjoy the most delicious food in the region.
Tip: when you visit the pyramids, make sure to take a bottle of water and wear light color clothes (preferably white). It will allow you to obtain more energy from the pyramids (for the people who believe on that) and of course, will prevent you to be sunburned!