It does depend on some indoor factors like whether you have lights, good south windows, greenhouse ... if you will transplant to larger containers while still indoors, etc.
Johnny's Seed supposedly makes it easy. Their starting dates seem a little optimistic to me, however. You too will get a feel for these things in your own location
@mydogdory . Timing is important so keep a journal of those early dates for a couple of years until you come up with your own calendar.
Here are Johnny's ideas:
LINK.
You will need your last frost date. Start with your state and you can find your official Weather Service one here:
LINK.
It's fun. You will have varieties you just can't find in your garden centers by choosing your own. Pinetree Seed has small packets at good prices and a good selection but they aren't the only ones.
Steve