How can I create double slabs and stairs?

Hello

I already know how to create a slab, but how can I make them join and form a block? Like the stairs when placing them, like the usual ones in minecraft

I would also like to do vertical slabs, but how can I direct them?

please, it's the last thing I need to finish my mod

Use Mcreator 1.7.7 or 1.7.9

I'm sorry, for my writing, I do not know very well English

Thank you for your attention or help