Many people feel awkward and nervous when first spending time with a suicide bereaved person. It will take some time to learn how to respond. It is okay to feel awkward but you don't need to let it prevent you showing support.
Grief due to death by suicide is vastly different than grief due to death by cancer.
Unless you have experienced death, sudden death or some type of traumatic loss, divorce etc, all of the ways we experience grief will be as different as our fingerprints for everyone. We usually can be real safe by giving hugs, saying, "there are no words, I am just really sorry to hear this" and then just ask for their guidance to help them through it.