Hi everyone i will ask questions because i started to learn some of UE4 and lets do this ok what i need to know is:
1 How much landscapes can i have in one level and can i some how make a LOD that my level not load everything just what camera sees if u know what i mean because its slowing my UE tooo much i mean on loading
2 Do i need every single land or landscape to cover it with Lightmass and Postprocess…
3 will be soon 
There’s a tool called World Composition that can be used to manage multiple maps together: World Composition User Guide | Unreal Engine Documentation
-If you are using a large landscape, then Lightmass would not be a good option, because that would require a large amount of disk space to store all of the lightmaps, and it could possibly require too much RAM for you to build since for each map it will have to load everything to build lighting, if you have lots of foliage then it has to load that all at once.
But i want to be seen everything in my level all landscapes what i have just i dont want to load everything like LOD i think i will try with multi map u say and i put all over one lightmass and postprocess
It doesn’t seem like you read anything I wrote
Yes i did but that is not an answer what i looking for i try that now still the same thing lots of waiting for light rendering and need to render landscapes separately this is one level with lots of landscapes
What are your PC specs? I’ve heard the building lighting takes up a lot of CPU power.
Intel g3220 3.00ghz 3.00ghz
If I found the correct processor, yours has a $60 price tag, and is dual core. In that case, I’m not sure there is a whole lot you can do about the actual lighting build time 
I recommend at least an hexa-core AMD, or quad core Intel processor for something like UE4, these usually carry a $200-400 for a good one. RAM can also bottleneck operations like this if you are running out of RAM while building lighting.