There's a SHOP icon on your screen and it is a one stop shop that players have access to at nearly every point in the game. Zeke will no longer be selling items for Crowns, and items previously sold by Zeke can now be found in the regular Shopkeepers of the worlds of the Spiral.
When you first open the SHOP, you will see several tabs across the top, each with a different icon. Here you can shop for items on sale, gold, mounts, elixirs, bundles of clothing, henchmen and booster packs.
Once you've chosen your purchase, you will be prompted to confirm your purchase, and your payment method. Some items can be purchased for both gold and Crowns, so make sure you're buying it with the currency you wish to spend.
Arena Ticket Shopkeepers
Some Shopkeepers only accept Arena Tickets. Arena Tickets are earned only through Ranked Player vs Player matches in the Arena.
Diego is an example of an Arena Ticket Shopkeeper.
Some worlds have secrets! Look for hidden areas that allow you to access special Shopkeepers and Trainers. Some of these areas are only accessible at certain times of day, so watch for clues!