Practice is the Key. Go to every single contest. And try to solve A,B,C. Do Virtual Contests. See how you perform. If you are doing these constantly but have no improvement, you need to learn new algorithms. But in the newbie level, Practicing is the key.

When you are solving problems, after like 2 hours of failure, read the editorial. Do Not read the code. Try to code yourself

If you're trying to improve at div 2 contests, I would recommend practicing all old contests with a difficulty greater than or equal to div 2, but that are not too hard (for example, div 2, div 1+div 2, maybe div 1).

Mike had an interesting blog that you can check it.

My tip is analyzing the example tests for deeper understand the problem and know what's the solution trying to do.

And like others, practice makes perfect.