Texturing map item / double terrains on maps

I'm so terrible because go figure instead of properly introducing myself, my first post on the forums is a map making question (I hope this is the right forum to post this in)

Here's my map so far. It's Hilly and not a flat plane I promise


But I'm running into some issues.

If I add in downloaded objects they are coming up untextured which is something I expected but I'm absolutely lost as to how to go about texturing them..

My other issue lays in the fact that I cannot get secondary terrain overlays to work in my life depended on it. As shown in the picture my first terrain overlay (the sandy beach) works great but when I want to add another texture, the texture shows up as black patches.

I've been following the map making tutorials but they aren't helping me with these issues so I'm hoping one of you lovely people knows what I'm doing wrong.


One not so dire question is there anyway while in free cam mode to make the camera "rise" or "fall"?

 

Well I feel plenty silly. My texture issues ended up being simply because I had assumed all the terrain textures that came with the game where png when in reality some of them are jpg. Whoops, that one was very much my fault.

It turns out my mesh texture issues where also an issue of my assuming things. As I'm used to using the mapmaker on another game I pretty much assumed that material files and adding textures would work the same way .. which they don't. But all is well not and you have served to be extremely helpful.

You were right about the Page up and Down keys controlling camera movement also. So thank you for you help with that aswell.