connection

how can i find ipaddress/host name of my system

Win+Pause will tell you the host name. IP addresses can be found through the network icon, which changes in every version (and you don't tell which one you have) so it's possibly easier to just run ipconfig from a command prompt.

Now, I wonder why you think you need that information in the context of HeidiSQL. If the server is complaining about wrong credentials, it'll tell you IP address right in the error message.