End Condition control_ so much hard to me somebody help me?

I try to make end condition in blue box.

like this. but I dont know hot to make like that(i see that photo in youtube, but he not explain how to make that)

1. how i can make end condition at end of road???(hope to know search word or tutorial!)

I only know make end condition use for linear template,

but when i open another file, end condition made by mesh and look good(for control)

2. Can share how to make end condition like that? if i know how to make end condition like that, i think i can make terrain more clearly in my project.(If making end condition by mesh, can calculate fill or cut amount?)

3. i think need to block between two different end condition(made by linear template), there is any function for merge that??

4. Pink color end condition and sky end condition need to cut or merge, but don't know how to control that. (wish to be know for search word)

My Question is so much.  but i find in Youtube, Google, and here(I think can't find because my English is bad)

So even just teach to me search word for fix that problem really helpful for me!