Professor Messer is a widely recommended, free video course series covering CySA+ in full, produced independently but closely tracking CompTIA's exam objectives release after release. For candidates on a zero budget, it's often the first resource recommended in CompTIA study communities.
What the free course doesn't include is any tracking of your individual progress or readiness — it's a video series you watch in order, supplemented by separate free practice questions, with no diagnostic and no adaptive plan built from your specific gaps.
Edureify's curriculum covers the same CompTIA exam objectives, but the Diagnostic identifies specifically which of threat detection, vulnerability management, and incident response you're weakest on, and the roadmap keeps you there until your Readiness Score improves — which watching videos in order doesn't measure.