Game crashes when launching after build, is it related to my main menu?

Hi, I’m brand new to UE4.

I was trying to make a main menu using this guide: https://docs.unrealengine.com/latest/INT/Engine/UMG/QuickStart/3/index.html

I’m also using the GameAnalytics plugin, and running windows 8.1.

I made the blueprint, saved the files, clicked “build” and clicked launch. I get this every time:

“LogPlayLevel: BUILD FAILED
PackagingResults:Error: Error Launch failed! Unknown Error
LogWindows: LaunchURL http://gameanalytics.com
LogDirectoryWatcher: A directory notification for ‘…/…/…/Engine/Plugins/’ was aborted.
LogSlate: Took 0.008998 seconds to synchronously load lazily loaded font ‘…/…/…/Engine/Content/Editor/Slate/Fonts/DroidSansMono.ttf’ (77K)”

As far as I’m concerned, thats not telling me what exactly is wrong, so i’m really confused about the whole thing.

I followed the guide step by step until i reached "18. Open the First Person Character Blueprint inside the Content/FirstPersonBP/Blueprints folder. " in the fourth page of the guide. I wasn’t using the first person template because I didn’t want to start out with a bunch of pre-created content to clean up, but now i wonder if i missed an important function because of it. Do I have to make a sort of gamemode or something? Even when I build a level in the viewport and then try it it doesn’t work, so I guess its not relying on a level.

So sorry for the undoubtedly stupid questions I’ve asked, I’m sure you are all smashing you heads against your desks in agony reading this.

Any help would be great!