where can i get enchantments to improve my weapons and armory.My enchantment list is empty.I have items and i have gems,but my enchantment list is blank.Please help

You need to disenchant magical items when you are at an enchant table. The items you find or even the ones you can buy. Then the enchantment will be known and you will be able to enchant it on an item.

Enchantment "power" is linked to your enchantment level and chosen perks. And It is also linked to the "strength" of the soul gem used (Black/Grand being the highest).