@deathbychoc1511 - items you buy go into Inventory for you to place later
Tap the crossed arrows, bottom right, to go into Design Mode
Tap the icon that looks like a box, lower left, to open your inventory
Tap on the Homer Icon in the top left of the pop-up to view stored Characters
If you can't see the Homer Icon you're in a sub-section already, just tap the left-pointing arrow in the top left of the pop-up to go back to the main Inventory section.
It should show up in that list ready for you to place
EDIT - the main Inventory section shows everything stored. If you haven't stored many items it'll be easy to spot the Bowlerama there rather than checking the Characters sub-section