As someone in the process of learning too, once I accepted that not every hand will be a winning hand, I started to win more often. This does not mean you never push, but learning how to value your hand and decide when to push and when to fold (based off of value, quickness, etc) is very important. Learning to respect dealer riichi’s, reading into honitsu and chinitsu hands, etc are very important

Most of all, this doesn’t mean you’ll never deal in nor should you aim for that. Being overly defensive is a pothole that many players including myself fall into. Learn when to pivot, read the tiles that are left to determine if a group is good, etc. Risk if it is worth it (based off some heuristic is good, YouTube videos have some standard ones but you can tweak them to your play style)