After breaking out of your cell, kill the Goblin and walk to the table. Look at the pile of garbage in the corner. Take the bone on the left (in the pile of vegetables) and use it on the chair ten times to get new items in your inventory.
If you have the Bless spell and an Ylside armor, you can put it on them even if you are in the 10th level of Strength. Use the Bless spell (your level of magic is important at this point) and put on the armor and weapons. When the spell ends, you can still wear the armor.