First reading read roughly

In the first reading,you read marking unknown words and phrases.
Then you should use different mark or color.

It's surely needed for you to infer the meaning of words from the context.
So you ought to read book infering withought dictionary at least one time.

It also useful to note original marks on composition of sentense or how to use that you feel difficult. You should note them with a tool which can be erased.

Making the book dirty prevent you from reading again. So it's good to erase them when they're solved. After first reading, you should start second reading straight.

You read roughly putting dictionary beside you and divide in short part, and then start checking second. As a result, you can deepen the understanding more.

More and more long time you spend from the first reading to the second reading,you're likely to forget the important part you can't understand or care about.

point :
After first reading,you should start second reading straight.