Hi Martijn - yes, you most certainly can keep adding matches for future dates. The best way is to login to the admin panel and click on New Match from the matches screen. Yell out if you have any problems.

Ok thank you thats great! also can i change club names after i created them? yes; please where? thank you

Update: you can now go into Setup/Clubs and click "edit" next to the club name and change your club name yourself.