The second map16 page in the VLDCX base ROM looks like this, despite a few tileset and palette variations:
You should be familiar with what most of these tiles are - and if you don't, check their "Act as" setting and play around with them -, but it's worth noting a few things:
The highlighted part uses BG3
and palette 1
instead of the usual FG3 and palette 2 the ground tiles and a few bits from the ghost house tileset use. So if you want to mix two different tilesets, please prioritize utilizing BG3 so you can make use of this page
instead of doing it in your own page and filling up space unecessarily.
Also, the purple triangles are there to indicate that every tile in the two bottom lines is tile 1EB, the tile that you put below a triangle to make it function.