Of course! Oradea, Cluj-Napoca, and Sibiu are all beautiful cities in Romania. Here are some helpful travel tips for your trip:

Best Time to Visit:
The best time to visit these cities is from Late April to Early October when the temperature is mild and pleasant, and most of the touristic sites are open.

Route and Accessibility:
The cities are well-connected by train and bus routes. You can start from Oradea, then move to Cluj-Napoca and finally to Sibiu.

Altitude and Acclimatization:
The altitudes of these cities are not very high, so you don't need any special acclimatization. Nevertheless, if you are planning to go hiking in Transylvania, make sure to acclimate yourself gradually to avoid altitude sickness.

Accommodation and Booking:
There's a wide range of accommodations available from budget hostels to luxury hotels. Ensure to book your accommodation in advance for peak season travels.

Clothing and Essentials:
Dress according to the weather. Carry a raincoat or umbrella for unpredictable weather conditions. A good pair of walking shoes is recommended as you'll be walking through the cities.

Health and Safety:
While Romania is generally safe, be aware of your surroundings, and take care of your belongings.

Local Etiquette and Respect:
Romanians appreciate respect for their local customs and traditions. When visiting religious sites, dress modestly. Also, learn a few basic Romanian phrases, it might help you connect with the local people.