New to this Forum - Requesting feedback on layout

very good 

Not sure what transformer you're going to be using, but I would not have any concerns about running 2 trains on that layout. In fact, if you are sticking with LC, LC+ and LC+2.0 you could probably run two trains on the outer loop and one on the inner using  one of Lionel's Universal Remotes.

As far as power goes, you should definitely use multiple power feeds/drops to both tracks to insure consistent voltage all around the tracks. 

You might also want to consider bringing the O-36 inner loop all the way back across to create a reversing loop - it looks like you have the space and, if necessary, you could relocate the crossover to another area of the track and use "tighter switches" - like O-72's. 

As said,  you need to use multiple power connecttions to the track maybe one on each straight and of course keep the two loops to separate controllers.   You can use DPDT toggle switches to change the power from transformer to transformer.    You can get tricky and break the loops up into segments so you can move trains back and forth from loop to loop - not continuously but with holding one while moving the other.

As for track plans, there are probably as many opinions as there are forum members!    I would put the two yard/stub tracks longways and eliminate that little inside loop.    Use the two switches to make a reversing loop as mentioned or per perhaps a passing siding on one of the loops.

Looks okay to me.  If you already own all those 10" pieces, that's cool.  If not, get some 30" pieces where appropriate.  As for power, use what you have right now.  If you run into problems, then make changes.  I think you'll be alright.

Welcome aboard, Joe.  Your track plan is a good one.  What the previous posters have said about having enough feeds is good advice.  We will look forward to your and your son's progress.  

1) You will get so much info and opinions here it can be overwhelming

2) Start out simple. Learn and go from there. Read and research as much as you can

3) Looking at you design be aware of your reach. It's not easy to reach over 3' or more

4) Last....have some idea on what type of layout you want and what size trains you want to run. Are you looking for more of a toy train layout w/accessories or high rail with switching....or maybe a combination of both..either way it's all up to you ....

Main thing it to not get overwhelmed and have fun running trains!!!!

Good luck and enjoy!!!

Joe