With respect to advaita vedanta I would recommend the YT videos of Swami Sarvapriyananda. All of his longer talks on advaita say more or less the same thing so recommending a single video is more difficult, but this may be a particularly good one: https://www.youtube.com/watch?v=EijmfagFw20. The main figure of classical advaita is Adi Shankara. You can probably find some translated/commented texts of his in book form.

If you mean more generally the whole of classical Indian philosophical thought it is really a vast subject of which I have barely begun to scrape the surface, so there's not a lot I can recommend there. I'm mostly still at the stage of reading related wikipedia articles.

EDIT: One more thing I should add is that there were also heterodox schools which explicitly rejected some or all of the assumptions of Hinduism (such as reincarnation). For example Charvaka (https://en.wikipedia.org/wiki/Charvaka) was a materialist school.