Problems getting started with ionic

Hi Guys!

I’m new to ionic and trying to install it using this guide :

Now everything works, i can create a project and add my android platform and im able to emulate android. But when i try to insert the command “ionic build android” i get these errors:

Id really like to get started soon but I don’t know what to do since I carefully followed the instructions in the guide.

All help would be greatly appreciated! Im not super computer savvy so please dumb your answers down a little bit if possible.

Thanks in advance guys!