Focus on making your code consistent with the existing style. Don't make big changes to code bases when you first see them, no matter how much better you think you can make it. There's nothing worse than a new dev who thinks they know better messing up code by trying to do refactors in their first week on the job. Don't suggest big changes to processes until you really understand current ones. After you've been there a few months and really understand the codebase, by all means, refactor away and make suggestions for other improvements.