that's a load of questions, the very general ones are best answered by a travel guide such as Lonely P. ect
2- the city is divided into 22 districts. No 1 is the very city centre, no 2-9 and 20 are also close. This system has it's limits but as a rule of thumb: When looking for accomodation, check its postal code as it tells you about the proximity to the inner city 1010 = 1. district, 1020 = 2. district, 1210 = 21. district, ect.
4-public transport is a good bet. Buses, subways, ect bring you everywhere and are reasonably priced for Western European standards. A 24-h-ticket is good choice if you have several stops during a day.
The yellow and blue rental bikes which you find all over the inner city districts are your sunshine alternative. You can register with your credit card, the first hour is always free - enough to go from A to B.
5- As you travel in June, the Summer Stage might be already open. It's a nice terrace at the Donau, good food, always busy with locals.
The restaurants / bars at the Museumsquartier (MQ) are also recommendable if you wanna get a summer feel for Vienna - plenty of young people & students, often live acts or artists around.
Have fun,
lobopequenoMostly miss the great possibilities for long distance runners in and around Vienna. Run the Prater and completely forget that you are in larger city.
Picture shows the Giant Wheel, Prater.

