Can't log in

I bought gmod today but my is not working and i cant log in on help please! :’(

And you are sure you are using the right username and password?

sorry for my english because iam czech and thats not the problem, the problem is that when I click on Sign Up through steam so the page does not load and appear Timeout connection or something like that (incidentally, I use Mozilla Firefox but when I try to go to the Community tab within the Steam client and it also does not work)

Link to steam page please? ←this isnt working for me… PLEASE HELP!!
When I try to connect through Steam there so there shows: Failed to load web page (unknown error).-118

PLEASE HELP ME!! It says something with firewall but it dont work