Cairo is a huge and chaotic city but that is part of its charm. Accommodation is spread out around the city and caters to all budgets. A good area with a few budget hotels and lots of good cheap restaurants is Orabi, 1km south of Ramses Train Station. Getting around Cairo is much easier than you would imagine thanks to an efficient metro service. Although it does not cover the whole city it does get at least close to most of the main sites and attractions in Cairo. The system is easy to navigate once you get used to it, the service is cheap and the trains run frequently. Tickets cost between 3LE (0.20USD in 2020) and 7LE (0.44USD in 2020) for a ride.
Trains to the south leave from the Ramses Train Station. You can get there on the metro, the stop is called Al-Shohadaa. Buying your train ticket can be a bit confusing as there are different ticket offices for different trains. Ask around and be patient. It is also better to buy tickets a day or two in advance. The train to Luxor takes 11 hours and costs 195LE (13USD in 2020) for a first class seat. To Aswan it takes 15 hours and costs 235LE (15USD in 2020).