Of all the layouts ( at least ten) that I have built over the last 60 year or so the most successful were the last three that were a so called "dog bone" type.
A dog bone is and oval that is squished down in the middle resuling in a double track railroad with return loops at both ends. It is basically a continuous track. The benefit is that you can put staging sidings in each of the end loops and hold trains there and release them whenever the timetable calls for their entry on the "center stage".
Trains that depart to east, return from the east as in real life. I disdain any layout, which is most of the ones in books, whereby the trains that leave to the east return from the west. Does this make sense to you.
My method of designing a dogbone is to draw two parallel lines across the page with a balloon at either end. Then I sketch in the sidings, stations, yards and whatever else I want in a logical arrangement. At this point you have determined all of the salient points needed to arrange that railroad on the available space. Now you should mentally operate trains on this imaginary raiload. The time to debug it is now, before you do anthing else.
Now you are ready to design your layout, which you are confident is what you want to accomplish.
Put one of the balloons in a corner where there is space for it. You can stretch the distance between sidings, add passenger tracks at stations, and then wrap the track around the existing space until you come to the ballon at the other end. I usually put the staging in the end loops under the upper level so trains are arriving out of a hypothetical location. In the case of the layout I am now planning, one end represents New York, and the other Boston, with the New Haven Union Station in the center. From New York to New Haven I will be adding two more tracks to represent the four track mainline that is in place there.
You have ample space to work with so go with the largest minimum radius that fits. I have never used lesss than 30 inches because I run large engines and 80 foot passenger cars. In my new layout, I will have room so will opt for 36 inch minimums. In corners, there is no need to scrunch down, you will find that using a much larger radius not only looks better, but doesn't really take up that much more room except to reduce the tangents leading to and from it.
Give it try, part of the fun is designing your own layout, there is no fun in just copying somone else's ideas as your own.
Modeling the New Haven Railroad in the transition era