I think it is a pretty even split on starting with ancient history (this is the approach Simply Charlotte Mason’s materials are slated for) or starting with your own country (American history I’m guessing? Canadian? Wherever you are.).
The next decision is how many times you want to cycle through history. SCM does 6 years, more time on ancients/biblical history than a lot of other curricula. Many do a 4 year cycle (ancients, middle ages/renaissance/reformation, early modern times (colonies up to the civil war), and modern times (civil war to the present day). I think there are even a few that do 3 year cycles.
And after you decide when you want to start you will quickly realize that any other children you have will start at different time periods if you are keeping the family together, so where you begin with this first child really doesn’t matter. Do what sounds most interesting to YOU. 😉
Not sure that is a lot of help. Ask more questions any time! Also, SCM has a wonderful learning library under the Learn & Discuss tab at the top of the page. You can look at blog posts they’ve done by series or by topic. Series is a great way to start, then you’ll see options for a series on getting started, or a series on the early years, etc.