nah... I think you'd be ok to have at it. I was a novice the first time I changed mine... (I'd highly recomend a haynes manual though) For the filter, just pull it out and take a look at it. Someone owning a festiva would know better, but it should be in a rectangular box with the top half clamped down. Nothing too it other than take it out, put a new one in...
Plugs, take the wires off (only one off at a time so the firing order doesn't get messed) and use a plug socket to unscrew them and pull them out. the haynes manual has color pictures of what the plugs should look like if I remember correctly... but they should be dry and a little black/sooty.
try this link to give you an idea:
http://www.jonko.com/forum/tutorials/basics/plug.htm
one other thought... on some engines, a bad valve cover gasket can cause oil to leak down onto the plugs... so if you see that.. that's what's going on.
hope some of that helps