Blender and Cycles.

Blender and Cycles will be free and open-source forever?
I’m new to blender.

Forever is a very long time. I don’t think you have anything to worry about.

While no one can claim to know what will happen “forever”, everything that has already been released will forever be Open Source, and chances are anything created by the Blender Foundation will remain open source for the foreseeable future under the GPL license.