Until you can reliably deliver what you thought you could deliver, focus on how you define and build software. You don’t need Lean or Kanban or to improve your stand-up meeting. You need to learn how to define, build, and deliver software.
Don’t be distracted by nuance if you can’t get the basic gist correct. Deliver what you say you will deliver. And only work on that until you can do it. Be functional first. And then work on refinements.