What should I learn

Hello everyone, I just took my two CS classes and these were the fundamentals, I feel like I didn’t learn well enough since I am still struggling with Java , I kinda understood the fundamentals but I still struggle, do you guys think is a good idea take the CSx50 course from Harvard to nail the fundamentals and then take either a course of Java to learn it well or for example do the odin project instead? Thank you guys in advance.