The vast majority of Bachelor programs in Germany are taught in German, so most people who want to study in Germany need to have C1-level knowledge of the German language.
However, whether or not you need to attend a Studienkolleg (STK) depends on your previous education and not on your German language level.
The STK offers a way of acquiring the university entrance qualification (Hochschulzugangsberechtigung - HZB) if you have not completed the necessary education or if you do not have access to necessary documents. German language courses are part of the classes that you take at STK, and passing the final exam provides you with a C1 qualification in the German language.
If you are interested in a specific university offering a program in English, it is important that you check very carefully if the preparatory program is also in English. Please be aware, that many of the courses taught in English have fees. Always connect with the university you are interested in to learn more about their specific requirements.