I had the same question and came across a book called "Sophie's World" which tells the story of philosophy in human history, starting with Socrates and coming all the way to modern times. https://en.wikipedia.org/wiki/Sophie%27s_World

I'm currently about half way through, i think the book is geared towards a younger audience but i'm finding it really enjoyable.

Once you have a high level view of the highlights of philosophy, you can answer for yourself which philosophers to deep dive on.

Not parent, but like i said in the thread above, if i were you, i would start with the ancients.

Every fundamental topic that later philosophers discuss is there, and discourse is much simpler.

For full comperhension, some googling of greek terms is required, but it's not that big of a deal in the age of /r/philosophy and communities like that. Also, feel free to hit me up if you have any detailed questions :)