I had my diagnosis 3 years ago and it's a continuing process of discovery and change. Consistency important and so is rest, including good sleep.
I started off using exercise for better bones by Margaret Martin, but after a suggestion by my aunt a year ago I have joined the local gym under exercise referral scheme from GP( not volunteered by them) so I had help in devising an exercise programme which has been adjusted a few times.

I now go to gym twice a week, less than I started with but I do a good hour and also do other things.

At home I do plenty of heel drops first thing when boiling the kettle. I also fit in 10 lunges and squats in the morning, not that many, this is a new thing i was recommended, not too many but i try and do this every day. Also standing away from wall and impacting hands against wall, to stimulate bone building in wrists, to hopefully avoid fractures if falling.

I also climb on first step of stairs, one foot at a time, then go down, one foot at a time with impact. I also do this standing sideways on stairs, starting on first step. Not sure what these are called, just found first version called step ups. I had a few weeks seeing a physical therapist who had done a course about osteoporosis recommended exercises, lots of other exercises I don't do at the moment

I have also started yoga again very recently, find 12 poses for osteoporosis recommended by loren fishman. These have been proved to build bone safely.

Also as my spine is worst I have started doing bird dog and dead bug recently, just 10 of each, not even each side. I do them slowly and carefully and again focus more on consistency.

Unless you are really keen it is so important to find an amount which is achievable and can be repeated.

I don't particularly enjoy the gym, but i stick with it. Likewise my other exercises. I think the yoga has more potential for me to become more enjoyable.

As far as I know cycling and swimming not bone building, but if you like them that's good. Focus though on things which will build bone. I enjoy walking and know fast walking meant to be good and using hiking poles energetically likewise, my walks for enjoyment though, even though I use poles, more for posture and safety.

There are loads of other things which may be suitable for you, weighted vests, vibration machines, jumping.

I would say do research, take care to avoid flexion of spine, be conscious and work on posture.

And find a way of being positive though we all have our moments. I was really stressed for a few months when i had diagnosis, it was very difficult to focus and research without getting depressed, the official channels do tend to be rather doom and gloom which doesn't help.

Also be reassured you can get improvement, though other health factors will impact. I had a high thyroid for a while, and an hrt problem for a while. I do take a high blood pressure tablet, must admit I haven't really checked but probably not doing me good in some way, I know they are calcium blockers which sounds alarming.

So despite all this I have built bone and hope to continue to do so.