I bought premo Sculpey clays and made some cool designes but my problem is I
can't figure out how long to bake them.
I've already burned one.

Get an oven thermometer. Ovens are often off by 5 or 10 degrees, or even more.
~~
Sooz
To live a creative life, we must lose our fear of being wrong. ~~Joseph Chilton
Pearce