There is a Go button at the right end of the address bar unless you have done some tweaking to the Firefox toolbar buttons. You see that only if you have entered an address into the URL bar manually. You can also use the Enter key on the keyboard.

You already appear to be on the latest version of firefox if the information aside is from the computer you are talking about.

The only google related problem I recall that is frequent is loss of the google toolbar, and that is because google no longer support that as a firefox option. I can point you to further info if it helps.

I use firefox on an XP myself, but I am not certain what you are asking about a stop button and an internet connection, maybe you could provide a link to some of that info.

For general information you may find this helps:

• Firefox cannot load websites but other programs can <-- clickable link --

You have Windows, and I guess Internet Explorer does that work? (If so it may make it easier to solve any firefox problems you have)