First to clarify, by climbing you mean rock climbing correct?

Without the full picture (the first thing I do with a client is an in-depth questionnaire so I can have a good overview) here are my general recommendations for a 46-year-old out-of-shape woman.

1. Strength training — 2–3x a week. Bone density and muscle mass are both serious concerns for you at this age. Strength training with a kettlebell or barbell is the simplest way to do this.
2. Basic recovery. Sleep (7–9 hours a night) eat well (protein and produce), have good stress management techniques (for example mediation)
3. Find a community around the activity you like. Climbing gyms are great for this. But you can also connect with online communities focused on your interest where you can learn more about the things that you enjoy doing and need to do to stay fit.

Hope that helps!