How would I setup my camera to get a result that looks like Enter the Gungeon?

doing 2D sprites in a 3D environment is wonky in general. it takes a lot of tinkering and fiddling around with values but it can be done for sure. Even though it is more cumbersome i think looks much better this way, especially with parallaxing backgrounds etc. There isn't a one size fits all for this technique I'm afraid, but there will be countless of videos on youtube of people doing something similar you can check out.