How do the two half cells of Daniel cell know when they are connected? I'm currently studying electrochemistry in school, and there is something I don't can't quite understand about Daniel cell.

When you put $\ce{Zn}$ solid into $\ce{ZnSO4}$ solution, does the electrode become negatively charged even before connecting it with the $\ce{Cu}$ half cell?

I searched but I wasn't able to form a clear understanding, I read that the answer to the previous question is no, the the two cells need to be connected for the redox reaction to happen.
If that was the case, how do the half cells communicate, how do they know when they are connected even when there is distance between them?

If the electrodes were charged before connecting them that would make perfect sense for me, the electrons repel each other and when connecting the two half cells with a wire, the electrons move because of the negatively charged electrode, but from what I've read that is not the case?

I'm really sorry if that is a stupid question but I really can't find an answer.
No, electrodes do not know about each other.

When an electrode is inserted to an electrolyte, the electrochemical reaction is ongoing in both directions. If reduction direction overruns oxidation, the potential of the electrode is increasing ( or vice versa ) until the rate of both reaction gets equal, the net reaction rate is zero and the electrode reaches the equilibrium potential.

That may be quick or slow, depending on the electrode and respective reaction kinetics.

When both electrodes are galvanically connected, the electron exchange due the potential difference disbalances the equilibrium potentials of both electrodes and the net electrochemical reactions get the steady non zero rate.

Note that the electrode potential is conventionally referred to the Standard hydrogen electrode (SHE), which itself has potential $\pu{+4.44 \pm 0.02 V}$ ( Wikipedia ) wrt the potential of a free electron in vacuum. So saying $\ce{Zn}$ electrode potential is negative rather means it is less positive.



You may want to try searching various terms in wikipedia and following relevant internal/external links. The great source of compactly explaned topics is hyperphysics, but with limited scope. It is a kind of hyperlinked quick cards/cheat sheets, very handy, if you want to understand the basics.  This link is particularly for Electrochemistry