My parents are considering selling their home of 35 years which they only have 70k remaining on their mortgage.

Regardless, compounding is very powerful, and the more time you have the more powerful it is.When I was a child I read somewhere that one should try this: ask your parents to lower your allowance to 1 cent with the agreement that they will double your allowance each week: 2 cents the second week, 4 cents the third, etc.

Do you want to bank your retirement, or child's education fund, or hell just paying your bills on someone who clearly doesn't give AF about their life or someone else's?

(Owner got it from his parents for $1, so has nothing is owned on it.)

I live with my parents right now so I don't need to house hack, if I get a duplex it's getting rented out completely. 

Unless the child lives in the home Prop 19.

I may need a cosigner but my parents don't think I am ready to househack.

If you are a veteran or the child of a veteran then I recommend USAA - their landlord policy is excellent and not expensive.

If you or your parents are a veteran then you should reach out to them.

My tenant has a young adult child that was on the lease as a minor.