It's definitely easier to come at a problem if you understand what your program should do. Imagine that you are telling a child what to do and they are very smart, but they will only do EXACTLY what you tell them.
So, give your self a demo height that's easy and work with that. For example a height of 3. What would you need to do if you were to explain to a child how to draw it using a word processor? How many spaces would you need? How many hashes?
Instead of spaces I'll uses periods (.) so that you can visually see and count them. So, for a pyramid of 3 this is what you would get.
Notice that the right side lines up and the first hash on the bottom is at the first spot on the left. So, with a height of 3 how many spaces are there? What is the initial amount of hashes used? How is the amount changed? Notice that the spaces and the hashes are changed differently, so you need to take that into account.
So, as the walkthrough video says, you have a nested loop. The first loop will tell the computer how many lines to print and the nested loop will tell the computer how many times the spaces and hashes are to be printed out.
Good luck with that. Oh, one last thing. If you're still struggling with this, you might consider going to Scratch to do something similar which would help you understand the logic.
As for you code, there are several problems besides the logic errors. If you're going to declare an Int, you can do it one of two ways (from my limited understanding)
The first way is simply declaring it.
However, this is not complete was the variable 'n' has no value set to it. The second way to do this is to give it a value at the same time.
Int n = 0;
In your code, you started to declare a variable, but you didn't give it any value, and you also didn't end the line by using a semi-colon (;).
For this code:
It appears that you are trying to make a function or something as you have "return 0;" at the end. I don't think this is what you want at all.
However, there is no function declared anywhere. You just plunked that down without any conditions or statements. I'm not really certain how the computer will react to that, but it's not good, I'm sure.
The good news is that your code you wrote for the user input seems to be valid. I would throw everything after that part away and start fresh and use some of the ideas that the other posters have given you.