Hi sorry to hear you are having a few problems.
1st you do not connect to Mirc, Mirc is the programme you use to connect to a chat network. 2nd you dont mention any firewalls etc or operating system, this makes diagnosing your problem difficult. If you would like to post again with operating system info and any router/dsl/cable modem info, plus any firewall/virus stuff then I am sure someone will fix you right up.
In the meantime have a nice day
