How to read a novel that I can't really understand because of the complicated language
Do not read it. Authors or translators for the matter have no right to expect their readers to force themselves into reading.
Incomprehensible style or vocabulary indicate failing of author to reach his target audience. Or in the best case, you are not intended to read his book.
Strangely enough, the latter might be that case if author prefers recognition from his intellectual sphere while he does not see ordinary commoner worthy.
Not all authors consider readers their customers. Their books may be appealing for certain happy few. Those advanced readers can understand subtleties and appreciate demanding work.
The problem occurs when recommendation from those particular individuals reach hearing of poor commoner. It might lead to question such is this one.
I repeat the book in question might be great but if hard to swallow for you, do not bother - unless you feel intelectually enriched.
Start with the one who can understand and relate. Understanding and getting clear picture takes time.
But you can certainly get the clear view once you understand context properly. And here comes complicated language where contextual meaning will automatically lead you through proper understanding.
You dont have to force yourself if the book was written in a language you don't know about.and should the writing maybe too complicated,you have to get the main ideas only..no one knows very word in English as there are many words that share the same or similar meanings..