No clue what's giving you trouble, but if you can identify it then you've got something that you can ask about.
General advice on writing code:
It's important to have a clear idea of what you want to make happen when you write code, so before you start writing anything, make sure that you've got a clear idea of what it is you're telling the computer to do.
When things go wrong, you'll need to start making observations to compare to that idea of what you want to make happen. Device little tests that you can do to find if it's doing what you meant and where it stops doing so. When you find somewhere that it does something else, look up how to do that something and/or correct it.
Don't ever assume anything to be true, find out instead.
On memorizing stuff:
Focus on what is being done, what is possible. Don't bother trying to memorize function names and syntax, that can be looked up. Just get an idea of what you can do.
IDE's hide what is happening, that can be bad, there are many pitfalls with them. What you've got here is just an editor and a run button though, it's not super over-the-top.
There's vim and there's Emacs. I don't think there are a whole lot of (serious) people running any other editors in the command line. The problem with those two editors is that they have steep learning curves which might not be what you need while learning the basics of programming!
I suggest getting a plain editor, like gedit, and then run the programs from the command line, and use the command line instead of a graphical file explorer (you can start gedit in the background and continue using the same shell) and you might want to run a python repl on the side to try commands before adding them in your code.
If the exercises are increasing too fast in difficulty, then it's even more important that you've understood things before moving on. You could do them again, click those reset buttons as you go or just make another account. If you know exactly how things work then you can mow through exercises extremely quickly, and if not, then the extra time is well spent on repetition. You can also look for other material, like this: https://www.hackerrank.com/domains/python/py-introduction and use google to find out what you're missing. Searching for information is an essential skill.
Whenever you encounter problems, try to identify what is preventing you from moving on, and work on that, whether by googling or asking for advice or just think about it for a while.
And finally, people just starting to learn how to code start out with a huge variety of skills and mindsets, some are already in a place that is functional for coding, others have a lot that they have to change about how they think. Writing code requires attention to detail because the computer does exactly what it's told, it doesn't do "what you mean". It's up to the programmer to line up events to get the program to produce the desired result, and not everyone is used to expressing themselves that way, instead relying on others to fill in the gaps as they communicate.