I got it all fixed. I contacted my hosts support team and they fixed it for me.
Here’s what they said: “Dear Customer,
this is caused by the events_calander plugin. I renamed it in the wp-content/plugins folder to events_calender.old so you can log in and do what is needed. It may be that it’s not compatible with 3.0.”
If anybody else ends up having this problem just contact your hosts support tech team like mariozorovic said.
P.S Thanks a lot mariozorovic and you too ts230 for the help.