5 minutes to Vienna's main shopping street, 10 minutes walk to Schönbrunn, St. Stephens maybe 15 minutes, Ferris wheel/Prater about 25 mins with the bicycle, 20 minutes to copa beach - a shoreline with 20km length along the danube's flooding basin (swimming possible!), situated at the Vienna Westbahnhof U-Bahn and train station, Salzburg can be reached in 2,5 hours, on a clear day you see "Schneeberg" from the terrace, a mountain of 200m which is ~70 km away and can be reached by train in just over one hour...
We're happy to give tips but depending on your interests there are just too many things to do in Vienna to list them all here...