I will be in Orvieto for a few days before a cycling trip Tuscany by the Sea. What should I bring to wear for dinners, and could you suggest some less exspensive restaurants for a solo traveler? Thanks

If you are going to eat out in inexpensive restaurants, I would say some casual pants or a skirt and nice t-shirt would be fine.

As for restaurants, look for pizzerias, trattorias or cafes, as ristorante may mean a little more expensive. (At least that's the way it was once.) For better food, avoid "Menu turistico" places. You can probably make a good meal of an antipasto and pasta.

Orvieto is a quiet town...no fancy at all but very romantic and sightseeing that's why it worths more than on day trip!
Food is amazing, no too much expensive but avoid "Turistic menu".
For the best aperitivo (5 euros inclusive a huge appetizer) try the Champagneria Orvieto and then restaurant Antica Rupe for a great local food/ spend max 20 Euros inclusive wines

Citycyclegal,
Try trattoria del Moro and La Pergola

There is a wonderful gelateria on the left as you walk from the cathedral into town. I can't remember the name, but it has a big blue sign listing all their flavors.

Tuscany/Umbria cools down a lot by October. And it rains quite a bit. So don't bring summer clothes, something more springlike, maybe.

I second L'Antica Rupe. It was recommended by the concierge at our hotel and we had a wonderful meal that was reasonable. Our favourites at this restaurant were the cheese stuffed ravioli tartufo and pork tartufo. However, the cheese and tartufo pizza was out of this world. I think I've dreamt of it. Do you sense a common theme here? Whatever you do eat LOTS of black truffles - it was my favourite part of Orvieto!