Questions on a 1994 Damon challenger

I'm new to Rv'ing... We just purchased a 1994 damon challenger, it seems like it's been cared for well, there has been a few things I've had to fix on it but nothing I would not expect for a 1994. I do have a few questions for anyone that may know.

The book is not real clear on how to fill the fresh water tank, it states there should be fill near the city water connection, but I can not find it. Am I right in assuming that the tank is in line and fills through the city water connection?

I am also having problems with the generator not starting from the remote, it's a generac 5 kw. It will start from the generator but not at the remote on the dash, it appears the switch is good as when I test it there is power to and the contacts open / close ...

Any other things I should know about this unit??

Thanks in advance for any help