The videos are quite old now, but this playlist helped me immensely with getting a grasp of the mechanics: https://youtube.com/playlist?list=PLlhN4dECgNlBo56l4WUC9Abki1W27DCKQ
Specific shoutouts to the "common mid-game problems" and "steel production" videos for getting me past cycle ~150. GC Fungus and Echo Ridge Gaming make good, very specific tutorials that are more modern, but I don't care for their styles as much personally. Check em out and see if you enjoy it.
Also happy to help out here if you have specific questions!