This is really an interesting time period, as it's when many historians pinpoint the beginning of closely-fitted clothing and of "fashion" (that is, regularly changing styles) as a status marker as distinct from wearing expensive materials and lots of them.

Underneath it all, noblemen wore shirts and noblewomen wore smocks on their bodies, both of fine white linen (a tradition of dress that lasted for hundreds of years). On their legs, they wore hose (stockings) that were made of fabric that was cut and seamed, rather than knitted - these were cut on the bias in order to stretch and conform to the leg.

The first layer of outer clothing was made to fit to the body, lacing or buttoning closed and with long sleeves fastening on the forearm with buttons. The woman's garment, the kirtle, had long skirts while men's tunics came to the knee, but otherwise they were made along similar lines. (Previously, both had been called "cotes", but the term was falling out of use at this time.) At the end of your period, both men and women were beginning to wear, over the kirtle/tunic, the houppelande or gown: a loose garment with full sleeves, which was shorter for men and longer for women.

The nobility wore both fine wool and silk in many different weaves - there were a huge number of types of fabric made from these materials. I can't be too specific about them as it's not my area, but Fairchild's Dictionary of Textiles should be helpful here.

You may want to look for the books Fashion in the Age of the Black Prince: A Study of the Years 1340-1365, Stella Mary Newton (1980), Clothing Culture, 1350-1650, Catherine Richardson (2004), and The Medieval Tailor's Assistant: Common Garments 1100-1480, Sarah Thursfield (2015).