Legal Question in Real Estate Law in California

Yes, by seeking an order from the court. It would not be fair that as equal trustees you can veto an act the other trustee wants but the can not so the same as to you.

Unless the trust provides otherwise, co-trustees must act unanimously. See Probate Code section 15620. Apparently the writers of the Probate Code thought unanimity was fair. Of course, a court can order otherwise, and can remove a trustee who is acting highly improperly, but a court will npt usually interfere with the independent judgment of a (co) trustee,

Whether the sale of real property is require is governed by the terms of the trust. You need an attorney to review the trust.