If I configer plugins in the congic.yml for example changing the kills or something in an already set up mini game such as hg or painball or spleef will it corrupt my server or do something wrong?
It depends totally on the plugin and what setting you're changing. Any responsible plugin developer will label dangerous config options as dangerous. For your typical minigame plugin, I doubt you can do much damage by misconfiguring it. But if you're worried, then I recommend either running a test server on your own computer when trying out plugins and/or making back ups of your important data on your live server.
