0.1.0 is what I start with and move up from there. This is what I've adapted for Xploration By Adrian, although in my early years I was very sporadic and used 1.0.0, 0.0.1, and a few others. But I do recommend starting at 0.1.0 and going from there.
Per Semver, reserve a and c in a.b.c for A. You first official release and C. Bug fixes and patches. This is because a major version generally breaks older code. And patches simply fix bugs. This is all personal preference, 0.99.0 doesn't mean you have to go to 1.0.0, etc. I've seen some that go all the way to 0.218.42.