moving from localhost to hosting server

Hi All,

I made a webpage and would like to move it to a hosting provider. I already have a website in Joomla with this provider and sometime ago they installed wordpress for me and there is a test area that has wordpress.
The following questions I have:

1. How do I transfer my wordpress site from local pc to this “domain”?

2. I have not made a child theme yet. Should I make a child them first on my pc or transfer it to the hosting provider first?

3. Going forward, the people of the website will be able to maintain the website and I want to know how to back-up regularly. Is there a manual for this somewhere?

Thanks,
Naveen