It will most likely be impossible to live forever. First, in order to live forever, we'd have to transcend our universe's plane of existence. Why? Because it's destined to come to an end at some point. The closest bet that I could give you for living forever would have to be extending the average life for a very long time.

For those in the future that decide to keep biological tissue as their means of physical survival, there will only be so much science that we will be able to do to extend a lifespan. Maybe we could transfer consciousnesses from one body to another or even transfer our being into robots, but this raises a philosophical question. Is this even us anymore?

There is also only so much that we can do to stop tissue from aging, like the shortening of telomeres, but I'll assume that we'll be able to go further than that with robots. Still, the universe is going to end eventually, and though it is a LONG LONG ways away, "forever" is still a strong term to use when referring to it.

Hope I could help you bring up even more questions or thoughts to continue your educational journey! :)