There are very less tutorials for UE4 compared to unity. Even the packaging optimizing has a lack of tutorials. The documentation is not good at all and too generalized. And there is a lack of hints regarding to file size optimization…
Are there more tutorials coming in the future?
They are updating their tutorials constantly + there are tons of community tutorials around 
When you are stuck with something, dont hesitate to post a question into the forum! The community is always here to help with problems/questions 
Tutorials:
https://www.youtube/user/UnrealDevelopmentKit/playlists
https://forums.unrealengine/forumdisplay.php?12-Community-Content-Tools-and-Tutorials
https://wiki.unrealengine/Main_Page
https://docs.unrealengine/latest/INT/
and on other sides you can find much more
Also keep in mind that the unreal engine 4 is just around 6 months old. For example when you take a look at UDK, you will see that you can find much more tutorials about it on youtube → a little hint: Also take a look at the UDK tutorials, because especially materials, meshes, level design,… works the same in the UE4