I'm very bad at reading someones code. For example when someone on uni asks me to help him with code I just write it from scratch, I can't find the mistake or even understand thoughts of this person. I'm afraid that when I'm going to work in team I'll be useless. Can I even do something with this?

I personally would just take time out of the day to look at some code that's not yours (doesn't have to be a coworkers could be online) and get use to figuring out what it does without be told prior to reading it. You'll eventually get better at it, and debugging other people's code is just the same as debugging yours-unless their code is just plain awful and has no structure whatsoever- the "detective" skills of debugging come with time and practice. Wish you the best!

Sometimes it's helpful to take out a piece of scratch and a pen and map the data flow. Start at the logical beginning, and follow each step, noting what is happening to the data.

Also, if you know what a function or method should be doing, write some pseudocode out and then see his you would accomplish the same. That can help when trying to determine the logic flow.

Soon you will want to use other libraries with poor documentation (like Firebase) and you will have to study other peoples code

This will be a major problem as it shows that you understand syntax and not process.

hey, I'm just like you