Can my ex-husband foreclose on my property if he gets a judgement lien against my house?
I borrowed $15,000 from him to purchase the house, which I paid cash for.
I have been unemployed and have not been able to repay the money, no can I refinance without the steady paycheck. I am willing to pay as soon as I can.

Thanks,

He may sue you for the money, and most likely he will get a judgement. If he has a judgement he may do many things, in some places he could get a lien on the home.

Is there any documentation for the loan?

A lien only prevents you from selling the house until you pay off the lien.

It is a personal loan. It was signed by both parties and notarized.

I just need to know whether he can force the sale of the house if he gets the judgement against me or is it just going to be simply attached to my property?
Again, I do not have mortgage... So, he will be the first in line.

Thanks.

I doubt if he can force a sale.

When he gets a writ of execution, he could levy on the house. If there are no prior liens, he could in theory sell the house at an execution sale. The homestead exemption, in whichever state you are in, might save you.

I live in CA and my homestead exemption is far below what my property is worth. The title is clean so far, so he would be the first one...
What I owe him is about 10% of what my house is worth right now.
Can I set up any kind of trust to prevent the sale?

You can not do it now, or it will be obvious that you moved the properly only to hide it.

I have never heard of a court forcing a sale of your residence because of unsecured debt. With a judgment he can garnish salary, attach bank accounts place a lien on the property, but I would be very surprised if the court allowed him to force a sale.