it really depends on how the trust was written.
the way i write mine is that i give the successor trustee an immediate ability to open savings types accounts with which to have a safe place to deposit funds when received.
but to buy any other asset, the successor trustee must get permission from the beneficiaries.
and then i stipulate a process by which the beneficiaries vote, so they can give the trustee a yes or no.
but in your case, you need to get a copy of the trust, and see what it says. if you cant figure it out, consult a specialist.