Multiple problems

1.Visual Composer
i will use the frontend but it only load load load and is white i looked how to fix it but find nothing just in visual composer settings that there is no license key insert and secret api key what i have to do?

2. One Klick Install in WordPress
i installed the theme files with filezilla (transfer binary) to my server and i go in my wordpress admin place > theme options> one click install > if i click install it brings me a fatal error and i have to uninstall all from my server and make it new. how i install this one klick?

3. is there a description anywhere how to do step by step to insert my informations in the right area or a youtube tutorial i am a newbee and i learning by doing and it is hard to now how to do the steps what to do first second and so on

I am german and i understand english to talk together but its hard to write and read in this special words

i tested a little you see at csgo.esports-blogg.de but its just test because i have to figure it out what comes in wich space