Hello! It's great to hear that you're planning a trip to Hungary. Here are some detailed travel tips for you.

Best Time to Visit:
The best time to visit Hungary, especially Budapest, Székesfehérvár, and Eger, is during the late spring and early fall, typically from April to June and September to October. The weather during these periods is usually warm and pleasant.

Route and Accessibility:
Budapest is easily accessed by plane from many international destinations to the Budapest Ferenc Liszt International Airport. From Budapest, you can travel by train or bus to Székesfehérvár and Eger. Hiring a car for a more flexible schedule is also an option.

Accommodation and Booking:
For accommodations, there's a range of options from luxury hotels in Budapest to family-run guesthouses in Székesfehérvár and Eger. It's recommended to book your accommodation in advance, especially during the peak travel seasons.

Clothing and Essentials:
Pack comfortable and casual clothing. You might require warm clothes during evenings or if you are visiting in cooler months. Don't forget your walking shoes, sunscreen, a hat, and a raincoat just in case.

Health and Safety:
Hungary is generally a safe country, however, always keep your belongings in sight and be aware of your surroundings. It's also advised to have travel insurance.

Local Etiquette and Respect:
Hungarians appreciate politeness and respecting local customs. A firm handshake is common while greeting. Hungarian is the local language, so learning a few basic phrases may enrich your intercultural experience.