Joomla! Template Boxite - Item Support

hello, after installing joomla website runs on oyginalnej site! After changing to tm_boxite - Default page displays: 500 Internal Error
The server encountered an internal error and could not complete your request. what am I doing wrong
I installed helix plugin and I can only see "Coming Soon Title"

I installed

I assigned for example the right menu position for the menu, but i can not see it, do I have to install some extensions, to for example to see only the main menu?
I have one more question, Joomla buttons do not work, for example save, save and close.....
When I click them nothing happens....
ok, i fixed the buttons problem, but still can not publish any module, could u tell me what should i do now? thanks.
Ok I sent you details. thanks.
Yes, it seems to be fine now, so please tell me, what sould I do to have the same effect?
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It will be published after it has been approved by the Website Administrator.
Hi there,
where can I add Google Map API Key?
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