Hi Martyn, welcome to the forum.
With an 11x6 layout it would probably be best to have a sort of oval so at least your son and yourself can enjoy the trains going around. It doesn't have to be perfectly symmetrical and could be amoeboid or dog-bone shaped.
Then add a couple of focal points like a station on one side and a goods yard or engine yard on the other. This gives a sense of purpose to the layout and allows one operator to be occupied with some shunting tasks whilst the other is running on the mainline.
Where there is space in the middle, add scenery - kids love building and playing with this - even more than adults. Add roads with scale cars and busses.
With an 11x6 layout it would probably be best to have a sort of oval so at least your son and yourself can enjoy the trains going around. It doesn't have to be perfectly symmetrical and could be amoeboid or dog-bone shaped.
Then add a couple of focal points like a station on one side and a goods yard or engine yard on the other. This gives a sense of purpose to the layout and allows one operator to be occupied with some shunting tasks whilst the other is running on the mainline.
Where there is space in the middle, add scenery - kids love building and playing with this - even more than adults. Add roads with scale cars and busses.