Predestined death?

In our faith, is death predetermined as some believe? I guess that is the right way to ask if our time is up it’s up?

You are touching on several issues.
The first thing is to remember that God has two wills. His manifest will and his permissive will. For example, God said, “let there be light” and there was light (Manifest Will). God gives us free will, hence we can do things God does not desire to happen (Permissive Will). If you walk into a bank while someone is robbing it, you might get shot and killed. That is not God’s plan, it is the result of the robber’s free will committing evil. God permits actions he opposes. The alternative is to eliminate free will. Your death was not predetermined by God.
Part of free will is to do those things that enhance our lives and those around us. (Why we avoid people with a virus.). We also have a responsibility to care for the body and life given by God. Thus, we love our neighbor as ourselves.

The issue of being predestined comes from the thinking that if God knows when we are going to die, we cannot change it. Here is where I refer to the understanding that because God is outside of time, he knows things “before” they happen. Just because he knows something does not mean it is his will it happens. For example:
You may know from your life’s experience if your child does certain things it will have a bad outcome. Just because you knew it in advance does not mean you caused it to happen. Parents sometimes allow their children make decisions (and mistakes) so that they will hopefully grow wiser and learn. Because God does not eliminate free will when we abuse the gift and commit sin, does not mean that God always likes the way we use our free will.
Back to your question, when we die involves numerous potential issues. If we have a cancer, we can choose treatment or not, that decision may impact when we die. If a physician by mistake gives us an incorrect prescription, that may impact when we die. If we fail to look both ways before crossing a street, that may impact when we die. Just because God knows how we will behave, or when and how we will die, does not mean we are predestined to die at a particular time.

Your question reminds me of a joke, (I have no idea who’s the author.)
God gave me certain things to accomplish in my life before I die. I’m so far behind, I’ll never die!