Getting Web experience

[willpower]

I am looking to get back into i.t after a career break. I did computer science at uni and worked for one of the big 5. I have decided to pursue web design and am tinkering with HTML, CSS and wordpress. I understand I need to build up a portfolio and have approached my small local primary school because they have an outdated website. I suggested a couple of improvements that could be done and I said that if they want in the short term I could maintain their existing website on a voluntary basis as the person who does it does not get time to update it and parents want upto date info on it. I am sure I will be able to do it because even now their school secretary is updating it. Just so that I don't look totally ignorant when I go in since I haven't worked on a live website before could you please tell me what to expect when I go. For example,

1) in terms of updating the website what front end tool do you think they could be using if a non techie is doing it at present and

2)when I make changes to the html files should I take back ups of the ones on the server? I assume I will have to use ftp to download the server files, make changes and them ftp them up so should I keep local back up copies.

3)In the long term what software would you suggest to create a totally new website for a school. Do you think wordpress would be suitable and to create mock up designs for a website to show to the client what would you use?
Thanks alot in advance for any help/advice you can give!