What are my rights to a property if there is no formal document from my grandfathers will?

My question is in regards to my grandfathers estate and I am writing on behalf of my mother. My grandfather passed away two months ago and did not create a formal trust. The only thing my grandfather created was a three page notarized last will and testament that names my mother as the sole executor of his properties, bank accounts, etc. My grandfather only had two children, my mother and my aunt. My mother is attempting to do as my grandfather wanted and has filed for an EIN to begin opening an account in the estate name. The bank is requesting copies of the formal trust. They have been provided with the only document left by him, what other information or forms would they require? Would it be too late to establish the trust and is it necessary? My second question is that the will and last testament also states the executor can sell the properties without notice only subject to such confirmation of the court as required by law. The properties have multiple owners on the title. Does the executor need all owners to agree or can she sell as stipulated and distribute the money as stipulated in the document if the sale occurred?