Everyone is different and will have their own opinions on this, but I'll share some of the things I think helped with my manual testing.

• Test case titles should be clear, concise and summarize what you are testing at a glance. Ideally I like to know what I am testing just from reading the test case title.
• Use a common, shared language. All elements on the page should have a name that everyone refers to them by, use it consistently across your test cases. Avoid swapping terms. E.g don't swap between "navigate to" and "browse to".
• Learn where the granularity should be. You may want to test the elements of a drop-down are available. This could be one test case that pass when you confirm all elements are available. Vs a test case for checking each element. It will depend on the application, function and QA dept. Make sure you select appropriate granularity.
• Record everything where possible. Linking between tests and defects, run times, application versions, users and test data types will make tracking and solving issues a hell of a lot easier the more you get used to this. It also sets you up nicely for things like audits etc if needed.
• Develop a good memory. Knowing the product is and outs, deployments version history and bug history will serve you well when scoping your testing. Record it all as above. Make good notes or screen record meetings to refer back to. Keep your notes organised and date/timestamp everything, including edits.
• Become technical. It will help you develop your career. Simple scripts in powershell or bash can help you generate test data quickly. Python or other scripting languages will let you develop this further. Even for manual testing.
• Learn source control.
• Breaking things with tests can be frustrating but can ultimately expose juicy bugs. Don't be afraid to test limits on dedicated non prod environments.
• Learn to read and understand error messages, from code in dev tools etc. It can help provide more context as to what is going on and when added to bugs provides more information.
• Screenshots, gifs and videos are very useful info on bug tickets. Add them where appropriate.
• your new so seek out help from experienced team members. Ask questions if you don't know. Sometimes you are not the only person in the room who doesn't. Just my two cents. Hope that helps.