Much like the rest of the pages and content blocks, you are able to change the order of your items in a list as you see fit.
1. Select Content in the gray navigation bar, and click on the Page that contains your items block.
2. Locate the list block, and click and hold the Hamburger icon that appears on the left (it is three horizontal lines and the left side of the block). Drag the item into the order you’d like the items to appear in.
3. Select the green Publish button in the corner to take your changes live!