executor vs. beneficiary rights

What is the name of your state? CALIFORNIA.
I'm a 1/6th beneficiary of a trust but my another beneficiary is the executor. Real estate and household furnishings are included in this trust but the manner in which they are to be disposed of is not specified. Does a non-executor beneficiary have any authority or right to decide how these things will be disposed of? Or can the executor make unilateral decisions regarding disposition of these items without considering the wishes of other beneficiaries? For example, if the executor wants to give away all the furniture but the beneficiary wants to sell this furniture, who prevails?

For a trust, it's called a Trustee. For a will/probate estate, it is an executor/personal representative/administrator.

Unless the trust document gives the Trustee authority to give away assets, then the answer is, "No, the Trustee can't."