First time working on a car

You'll get plenty of help, here. You have a factory service manual? MUST have. You can download a 70 manual from "MyMopar":

http://www.mymopar.com/index.php?pid=31

Direct link:

http://www.mymopar.com/downloads/servicemanuals/1970_Plymouth_Service_Manual.zip

The above is Plymouth, but the Valiant stuff is pretty much the same. Only problem with this manual is you'll have to learn to diddle with the page numbers, as the viewer numbers don't follow the Mopar "dash" numbering.

I see that you don't have air conditioning, so this should be a pretty basic car to work on. What you have here, is the modern day equivalent to a "Model A" (Ford,) easy to work on in their day.