Q:

How to make homepage show in google instead of other pages? 

How can you get homepage to show instead of random pages?  Is there a special meta tag or something? 

A:

I did a search as you specified and I get your home page as #1.  However, if you do not, this is not a problem and therefore there is noting to fix.  Going beyond that, you will not be able to exercise control over how Google decides to present search results short of some level of SEO which never guarantees any result. 
Here is what is wrong with your search:
Without using the site: annotation before the domain, Google will return pages in the order of importance as Google sees it including pages from other sites.  Just using the domain name without the site: annotation opens the search up to any result that ranks for the domain name.  However, using the site: annotation limits the results to the domain only.  In this case, the home page is often the first page, however, this is not always the case and should not be taken as an indicator of a problem.