+1 on the suggestion to get a fit.

When I shopped for my current bike, I started with a fitting to get some recommendations on bikes to test. I did this after testing many, but without a clear idea of what to try. I find testing bikes is not easy and I most definitely did not enjoy the process: bike shops won't have the right size, some do less than a cursory fit for you to test; you may not know the neighborhood and might be concentrating more on where you are riding instead of the feeling of the bike.

With my old bike, I put too much weight on my arms and shoulders. They bike was somewhat big for me and I needed (and always will need) more work on my core. I admit that work on my core sporadically. I also put it to the test on the bike, by riding stretches where I keep my riding position but put no weight on my hands at all.