What free tools and tips would help me learn Java, JavaScript, and TypeScript?

Pick one language to start rather than trying to learn all three at once. JavaScript is a convenient first choice because you can open a browser console and experiment without setting up much.

Work through variables, conditionals, loops, and functions, then try a tiny calculator or to-do list. Breaking things and figuring out why they broke is useful practice.

Check what language your degree courses use first. If Java is coming up, starting there could make your coursework easier. Spend some time getting comfortable with one language before adding the others.

I'd leave TypeScript until you have some JavaScript basics. TypeScript builds on JavaScript and adds a type system, so knowing what the underlying code does gives you one less thing to puzzle over.

Use beginner guides and course materials when you get stuck, but try to solve your homework yourself rather than copying an answer. Even an incomplete attempt gives you something specific to debug or ask about.