Bike fit / correct riding position

first longish ride on the new bike yesterday and felt like I was putting too much weight on my hands, not enough through legs, and major shoulder ache. lack of fitness? anxiety (hunching)? seat too high? bars too low?

Saddle set too far forward, i.e. your saddle/bb distance sound like they're very short thus pushing you forward onto the handlebar meaning you have less pressure on the saddle but too much on the handlebar, it also cause you to hunch badly and give the illusion that the handlebar is too low.

IMHO etc. etc.