Hi,
Depends on how much storage your images use, Mitzi. The Unlimited plan ($9.95/mo) includes 1 gigabyte of image hosting storage, and the $2.95/mo Basic plan includes half that amount, or 500MB of space.
The Free account has only 100MB of space, and if you are using more than that amount of space now in you paid account, then the Free Tools space will be too small to hold all your photos. If that is your situation, your best bet is to use the image deletion tools to get your storage down to 100MB or less, and then downgrade to Free Tools.
If you are already below 100MB, then no worries.
Hope this helps.