So Taylor, what you seemingly want is for someone else to design a layout plan for you, based on your description, instead of learning for yourself how to design a layout ?
Summarizing what you have written so far:
Space available for 18-24" deep shelf layout is 10 foot down one wall and 8 foot down adjoining wall
H0 scale
“Modern age”
“Not too complicated”
“City buildings”
“I would like at least 3 industries to switch that would keep one, maybe two people busy”
“would like a warehouse, grain elevator, and something that takes tank cars.”
“would also like a industry that takes grain hoppers and one that takes boxcars and containers.”
“Grain Elevator, warehouse, and maybe an oil dealer or propane dealer”
You are probably not going to be able to combine “not too complicated” and “keep two people busy” on a H0 scale layout that size.
You have already been told that “modern” long cars in H0 scale might be a bad choice for a H0 scale shelf switching layout, but you have not responded to that.
You seem fixated on re-using some buildings and rolling stock you have, and yet you do not describe them very well. What do you mean by “city type buildings” ?
People around here is generally willing to help, but you need to put in a little more effort on your own if you want to get help.
As for suggestions - you could e.g. take Linda Sand’s 9x5 foot plan from the article “Big City Railroads don’t require big spaces” in Model Railroad Planning 1999 and unbend it from U-shape to L-shape (by cutting away the center part of the plan).
Here is one adaptation of that plan - in the figure below, it was expanded from 9x5 feet to 10x6 feet.
you get new designs from Stein. A remark on the last one.
It has a curved runaround; coupling or uncoupling on a curve is always a problem. Unless the radius of the curve is 5 times the length of the longest car involved. Using modern 1 foot long cars means a 5 foot (60 inch) radius. Choosing for 50 ft long cars (7" in HO) means you’ll need a 35" radius in the curve. (Unless all the coupling is done on the straight part; both cars involved have to be on the straight, which is quite a length when it concerns two 89 feet long cars.
In the last MR-magazine you can see another switching layout; twice as big as yours. It has 4 staging tracks. Every train holds a number of cars. When the owner runs a train a day, only after four days he would have the same cars back on his layout again. Having fresh cars the next day, to serve the spurs, is garanteed this way. If you do not want to spend so much room on staging, because your space is very limited, you can get fresh cars in a different way. From a convenient spot you pick them off your pike by hand and put new cars back on.
You can always combine designs: take Byron’s city with Stein’s yard on the wing; but you never responded to questions about your preferences.
Study the websides of Lance Mindheim and Byron Henderson. Both are professional designers and both start with lots of questions. If you don’t answer to them they can’t come up with a decent plan; same on this forum.
One general comment I’d make is that on a shelf type layout you have an advantage that you can use use broad curves and turnouts, since you’re not restricted by the width necessary to turn a complete loop to allow for continous running. I currently have an L-shaped shelf layout using 31" R curves and No.6 turnouts as minimums. Yes it takes more room than 24"R curves and tighter turnouts, but I find it’s nice to have something closer to prototypical track dimensions…plus I can run anything I want, including 85’ trailer train piggyback cars with no problems.