Advices
Use Git Properly
Naming
Naming: You should be careful about naming. You should use meaningful names for your variables, functions, classes etc.
Comments
Your comments should be as short as possible. You should write comments to explain your code but in general your code should be self-explanatory. You should not write comments that are not needed. You can explain algorithms, data structures, design patterns etc. in your comments. You should not write comments that are explaining what your code does. Instead, your code should explain what it does in a clear way.
Nesting
You should avoid deeply nested code. You should use early returns to avoid nested code.