The Store Menu should look something like the image below:
From this menu you can buy all sorts of items to help improve morale, or to help out during a raid. Items with a cost displayed in gray are more gold than you can afford and may not be purchased. The majority of items are morale items, with the exceptions being the Heal-Up Potion, Full-O'-Manna Potion, Rez Stick, Forgiveness, & Mysterious Orb.
The Heal-Up and Full-O'-Manna Potions may be used during a raid to fully restore a character's hit points or manna points, respectively. The Rez Stick can be used during a raid to restore a dead character to life, much like the Battle Rez ability. Forgiveness is a gift that can only be given to players that have quit the guild. This will make them recruitable once again. You may give morale gifts purchased here from the The Gift Menu, which is accessible from the The Town Menu.
Finally, there are a set of Mysterious Orbs that can be found throughout the game. If you collect all 7 a wish granting Dragon... wait, wrong game... If you collect all 7 it will unlock something special! If you are having trouble finding some of the orbs, you can purchase them from the store for a large amount of gold.
There are multiple pages of items, with 10 being displayed at a time. You can use the arrow buttons to go to the next, or previous, list of 10. The up and down arrow keys can also be used to traverse this list. To buy an item, select the Buy Item button at the bottom right of the screen (or press Enter). The Back button in the bottom left corner will return you to the Town Menu.