Most older digital cameras do not work when you try to use a memory stick adapter and the newer, smaller size memory sticks. Because this memory format is so old that it is no longer sold in retail stores, your best option is to buy a memory stick online. You can find these memory sticks on eBay.
To find more eBay auctions for these memory sticks, go to the Memory Cards
category on eBay. Then, on the left side select Format = Memory Stick, and Storage Capacity = 64MB and under.
In the resulting search, only look at the auctions that are actually for 64MB and under Memory Sticks - you will find a lot of mis-classified memory in the search results - items that are the wrong format (not memory sticks) or too large to work in your camera.