First time buyer Water question

[Layton Mor]

Hello,

I am purchasing my first home and super excited but Im worried about my water. 

I am buying a 1997 remodeled manufactured home with my own well. Inside the house the toilets and bathtub have yellow water. Its already kinda stained the toilet. When you open the toilet cover there is an oily filmy substance....hard for me to explain. I will try to attach pictures.   It has already passed the water test.

My question is, is this something I have to worry about right now or ever? 

Would appreciate any input at all. Thanks!