You can have 3 free shops but after that they cost 150,000sP. You can name your shop and add a description to welcome users when they visit your shop. User shops can also be changed into a gallery in the "Edit Shop" tab.
Each shop/gallery can have multiple categories added via the "Edit Categories". They can be added or deleted if necessary. The "Quick Stock" tab is useful if you have a lot of items in you inventory as you can easily switch items between your inventory , vault and shop .
The "Shop Log" tab hows all the items previously purchased by other users. The "Profits" tab shows the total amount in your shop till.