A lot of suggestions for fiction works in here, but not sure that's what you are looking for. If you're wanting something that's actually going to explain basic philosophical ideas and concepts that dominate academia in a concise and straightforward manner, a really good resource is The Cartoon Introduction to Philosophy. This is a comic book, but it uses the drawings and what not to visually demonstrate a lot of concepts, which is great, because many philosophical ideas are abstract, and heavier reading can become a slog if you're not familiar with what's being talked about. The explanations are also very straightforward, it does a great job distilling concepts down to their purest form. Since it covers the most popular and prominent philosophers and their theories, it's also a good jumping off point since you can see whose/what ideas resonate with you the most, and seek out works by that philosopher, or works that explore the subject to a greater degree.
FWIW I remember learning a lot from The Cartoon Introduction to Philosophy
:)
It's Cartoon Introductions Philosophy
Check Thriftbooks or a local selection because bezoz bad
Also The Cartoon Introduction to Philosophy https://www.amazon.com/dp/0809033623/ref=cm_sw_r_apan_glt_fabc_26C3ZJPH1AZYBCTBM8BF
I have 2 kids late elementary school/middle school. I bought this philosophy graphic novel/coloring book. Both found it fascinating.
The Cartoon Introduction to Philosophy https://www.amazon.com/dp/0809033623/ref=cm_sw_r_cp_api_i_SqVLFbD8MK24J