C1 requires you to read authentic texts (newspapers, novels, reports) without stopping to translate. However, jumping straight into James Joyce is a bad idea. for C1 use authentic language but cap the vocabulary at roughly 4,000–6,000 headwords.
If you want a structured roadmap, a coursebook is your anchor. These books cover reading, writing, listening, and speaking in a cohesive manner. c1 english level books
by Mark Haddon : Written from the perspective of an autistic teenager, the language is deceptively simple but the emotional complexity and unique worldview require advanced comprehension. C1 requires you to read authentic texts (newspapers,