Ba'alei teshuva often have problems with issues of kashrut in their parents' homes. Pots, dishes, and utensils might not be kosher or toveled. Consult a rabbi. Questions of bishul akum (cooking that was done by a non-Jew) might apply to non-shomer Shabbat parents, but the custom is to be lenient.

If the parent's kitchen is known to be non-kosher, food must be prepared with care (see How To Use a Non-Kosher Kitchen). If the parents do not lie to their children, they may be trusted as to the source of food and its kosher status.

Since we may not eat from dishes or utensils that have not been toveled (immersed in a mikva), you may  want to consider toveling your parents' dishes or utensils, or using disposable goods. In such cases, it is OK to use china that has not been toveled.