I made a little research and I found that Cisco offer a free course on their website:
The Packet Tracer file won't open. The lab instructions reference a topology that doesn't exist. The video series stopped in the middle of OSPF. Or worse—the free course you were following is based on the old 200-125 exam, not the current 200-301 . cisco ccna free course fix
platform. While the full CCNA series is often instructor-led (and can vary in cost), they provide significant free foundational content: Networking Basics: I made a little research and I found