Anyone who has had cancer surgery will still have cancer. single cancer cells cannot be detected until a tumor/mass forms. so no cure or cancer free?

Not true: Certainly there are cancers that have been able to be surgically removed and patients have remained cancer free and lived a healthy life afterwards. A "fatalist" may say there could be cancer cells undetected and only if they turn into a large enough tumor will they be detected, but that thought process holds true for the general population. Be hopeful your surgery was curative and be positive.

Wrong: All tumors have the potential to spread but the primary lesion is multiclonal with the population unable to spread until tumor gets larger. When a tumor is resected early it probably has not spread but if an occasional cell gets free the initial immune response of surveillance removes the 1 cell. Early surgical intervention has for most cancers, a 90% chance or better of cure.