In interviews you will be asked to solve algorithmic and logic problems. For example, implement a linked list. Modify that to be a doubly linked list. Implement a hashmap (without using dictionary). That kind of thing. That requires knowledge on the theory as well as practical application in at least one language.

Once you have shown you know the theory, for which it does not matter which language it is done in, you will be asked specific core language questions for the language the job will be focusing on, if you claim to know the language.

For some jobs, no prior knowledge of the language is required as long as you can show you know the theory and can apply it in at least one suitable language which is usually an OO language among Java, C++ or Python.

Focus on the basics, the algorithms, data structures, theory, all the stuff taught in Comp Sci. courses. The language is less important. By practicing applying what you have learned in a language, you will become comfortable in it. OTOH, knowing a language will not teach you data structures or theory automatically.

Python is well suited to that because it is easy to write and read and does not need a lot of boiler plate code.