If you want an overview of literally everything then read "The History of Western Philosophy". It's one of the very few things that philosophers actually have a consensus in saying that it is the definitive work in its field.

If you want to just get an overview of different topics in philosophy then the Standford Encyclopedia of Philosophy and the Internet Encyclopedia of Philosophy are your best friends. To get started on the big topics in each field check out these articles depending on your interest:

Ethics (What is a good action?)

Moral Realism - "Is there a universal good? Are morals relative?"

Virtue Ethics - "Virtue as the Good"

Deontology - "Intentions for the sake of duty as the good"

Consequentialism - "The consequence maximizing utility as the good"

Nihilism - "There's no point to life so nothing is good"

Existentialism - "Embracing the meaninglessness of life"

Aesthetics (What is beauty?)

Beauty - "Is beauty objective or subjective?"

Logic (A system of rules to seek objective truth without necessarily needing perception):

Classical Logic - "Deductive reasoning. If A then B; if B then C. A, therefore C."

Inductive Reasoning - "A has followed B many times in the past. If A, then B is likely."

The Problems of Induction - "What's wrong with it"

Epistemology (What is knowledge?):

A Priori and A Posteriori - "Knowledge independent of perception vs. dependent on perception."

Rationalism vs. Empiricism - "Knowledge through logic (e.g. math) vs. knowledge through evidence (e.g. science)."

Metaphysics (The study of the non-physical)

Grounding - "Objects relations to other objects"

Physicalism - "Everything is physical"

Let me know if you have any questions. I'll help you out as best as I can with what I know.