You can get around town inexpensively even if you don't speak a word of German. Get a guidebook, preferably one with a good section on transportation and a selection of helpful phrases in German.
Some guidebooks even explain in detail how to get to specific sites on foot or via public transit.
Use the affordable public transportation system. It's easy to use, and the aboveground trams are a great way to see the city without signing up for an expensive tour. Get a Vienna Card. There are a number of other transit passes available just ask at the tourist information office. Walk whenever possible.