Recovering from injuries

I just downloaded your app. I want to get started, but I’ve some some questions.
Here are my details:

I’m male 63 years old retired fitness and aquatics professional that had trained for triathlon until 56. Since then I was maintaining, and the last year getting back into cycling more seriously.
I fell , broke 4 ribs and a scapula 6 weeks ago. I’m starting a 10week Fitness starter, but I’ve lost so much leg strength and my VO2 max/ FTP have dropped by 10-15%. My HR has is much higher on Zone 2.

What’s the question ?

Sorry the lat part was cut off. What else can I do to get my rib cage back so my breathing returns to normal volume?