Is it possible to wire a 240v outlet so that after I don't need 240v anymore I will have two 120v circuits?
Yes, just be sure to run a 4 wire circuit (2 hots, neutral and ground), if the current garage is attached you don't need extra ground rods. In fact, since you are planning for the future, you might install a sub-panel now that would supply your EVSE outlet as well as other circuits in the future.  As many others have said here, go bigger than you expect to need on the sub-panel, they are cheap compared to upgrading later. It's OK for the sub-panel to have greater capacity than the feed to it...no problem.  Just make sure the breaker is appropriately sized for the wires feeding it.
You can't do this with 2 separate 120v cables, not code allowed.
EDIT:  Of course be sure the wires or cable are of sufficient size to feed the EV charger and future needs. (should have included that with my answer).  I also got ahead of myself regarding needing ground rods or not because I was already thinking about sub-panel. Clearly you wouldn't need additional ground rods if it was just an EV charging outlet.