About Note-tmaking

These days, I am really interested in note-tmaking.

Because, I wanted to remember many things after reading books.

However, most of things were gone awayI forget most things the next day.

It gave me an idea of how to usmake note-takings more effectively.

But now it is helpfuleasier to remember many things than in the past.

Because, I wanted to remember many things after reading books.

"Because" combines sentences in this case:
These days, I am really interested in note taking because I want to remember many things after reading books.

Because the first sentence is in the present, the second sentence also needs to be in the present (I wanted -> I want).
When speaking, you may hear it both ways.

However, most of things were gone awaythe next day.

Most natural: However, I forgot most things the next day.

It gave me an idea of how to use note-taking more effectively.

Both are correct, but this is more natural (idea how -> idea of how).

But it is helpfuleasier to remember many things than inin the past.¶
OR¶
But it is helpful to remember many things from the past.

These have different meanings and I was not sure which you meant:

The first means it was hard to remember things before but is easy now.
The second means the system helps you remember things.