Start with one official Cambridge test today. Diagnose your weakness. Then, and only then, go buy or download the specific materials you need to fix that weakness. Good luck. You’ve got this.

Do not just read. You need "scanning" skills. Use EAP Foundation (website) to practice finding synonyms under time pressure.

When you don't know what to say, say these phrases. They sound natural, not memorized.

Ace the IELTS: IELTS General Module - How to Maximize Your Score (Fourth Edition)