There is a tension between a State government's right to regulate activity within the state, and the Federal government's right to regulate activity between States.

Here the key question regarding interstate commerce should be about who must comply with this law (if it becomes law). California wants it to be "businesses" with a "nexus" in California, but that seems like rather expansive. But finding a more limited way to specify "California businesses" that isn't also de-fanged is very difficult in today's world.

Still, now, suppose that Texas or Florida had conflicting laws? Then what?

This impacts the entire world. Commerce clause is applicable here.