Admob google

Hello,
I have two questions.

1.Is there a guide to implement admob of google for androids?
2. Does admob google can show video ads? Most questions that had be made is about ad banner.
3.Although not related with ue4, but admob google is free right?

EDIT: After browsing in google for a long time, i figured that there aren’t questions about google video ads for ue4, does this mean, UE4 doesn’t support google video ads? It only support ads banner?

Thanks for the answer, this is about the admob of google.