Get fitted and try to get at least 105 componetry if you can. I am not big on anything less than 105 in the Shimano lineup as you will find you will want to upgrade soon. I am actually a SRAM rider so that is another story.

Some LBS’ do great fittings while others just do the basics of stand over and watch you ride in the parking lot to get an idea. If you find a LBS that does “real” fittings, well those can sometimes run you a few hundred! But if you are buying a $5k bike its worth it.

To a beginner, just let the LBS gauge you for now and get you in the ballpark. Good luck.